This 1988 Plymouth Voyager has a flashing turn signal issue. When either the
left or right turn signal switch is engaged, the turn signals light but do
not flash. The hazard lights flash just fine. Here is the wiring diagram:

http://webpages.charter.net/mrfixite...al-wiring1.jpg

At first one side of the turn signal lights were blinking but not the other.
Then, the working side went out too.The flasher was then replaced (eBay) but
that didn't help.

My question is what's the deal with the turn signal switch diagram in the
above linked picture? There are two, angled, thick black lines located in
the switch assembly (on the steering column). Which part of the switch
actually moves and which contacts get connected?

According to the continuity chart in the service manual, two sets of
terminals get connected when the left signal is activated. The first set
connects terminals 4,7, and 8. The second set connects terminals 9 and 10.
For the right signal, the first set connects terminals 5,7, and 9. The
second set connects terminals 8 and 10.

In the neutral position, 8,9, and 10 are connected.

I checked continuity on all these terminals and they checked out ok. By the
way, not shown in the picture are where the wires, D7, D6, D5, D8 and D4
terminate. Respectively, they terminate at the right rear turn and stop
signal lamp, D6 and D5 both go to the front end lighting, and D8 goes to the
left rear turn and stop signal lamp. D4 goes to a fuse.

Finally, approximately how much of a load does the flasher need to see
before it will open the circuit and begin flashing?

Thanks for your reply.
--
David Farber
Los Osos, CA

On 11/22/2013 01:00 AM, David Farber wrote:
This 1988 Plymouth Voyager has a flashing turn signal issue. When either the
left or right turn signal switch is engaged, the turn signals light but do
not flash. The hazard lights flash just fine. Here is the wiring diagram:

http://webpages.charter.net/mrfixite...al-wiring1.jpg

At first one side of the turn signal lights were blinking but not the other.
Then, the working side went out too.The flasher was then replaced (eBay) but
that didn't help.

My question is what's the deal with the turn signal switch diagram in the
above linked picture? There are two, angled, thick black lines located in
the switch assembly (on the steering column). Which part of the switch
actually moves and which contacts get connected?

According to the continuity chart in the service manual, two sets of
terminals get connected when the left signal is activated. The first set
connects terminals 4,7, and 8. The second set connects terminals 9 and 10.
For the right signal, the first set connects terminals 5,7, and 9. The
second set connects terminals 8 and 10.

In the neutral position, 8,9, and 10 are connected.

I checked continuity on all these terminals and they checked out ok. By the
way, not shown in the picture are where the wires, D7, D6, D5, D8 and D4
terminate. Respectively, they terminate at the right rear turn and stop
signal lamp, D6 and D5 both go to the front end lighting, and D8 goes to the
left rear turn and stop signal lamp. D4 goes to a fuse.

Finally, approximately how much of a load does the flasher need to see
before it will open the circuit and begin flashing?

Thanks for your reply.


10 years before that you could turn on the flashers and the ignition
would be energized.

"dave" wrote in message m...
On 11/22/2013 01:00 AM, David Farber wrote:
This 1988 Plymouth Voyager has a flashing turn signal issue. When either the
left or right turn signal switch is engaged, the turn signals light but do
not flash. The hazard lights flash just fine. Here is the wiring diagram:

http://webpages.charter.net/mrfixite...al-wiring1.jpg

At first one side of the turn signal lights were blinking but not the other.
Then, the working side went out too.The flasher was then replaced (eBay) but
that didn't help.

My question is what's the deal with the turn signal switch diagram in the
above linked picture? There are two, angled, thick black lines located in
the switch assembly (on the steering column). Which part of the switch
actually moves and which contacts get connected?

According to the continuity chart in the service manual, two sets of
terminals get connected when the left signal is activated. The first set
connects terminals 4,7, and 8. The second set connects terminals 9 and 10.
For the right signal, the first set connects terminals 5,7, and 9. The
second set connects terminals 8 and 10.

In the neutral position, 8,9, and 10 are connected.

I checked continuity on all these terminals and they checked out ok. By the
way, not shown in the picture are where the wires, D7, D6, D5, D8 and D4
terminate. Respectively, they terminate at the right rear turn and stop
signal lamp, D6 and D5 both go to the front end lighting, and D8 goes to the
left rear turn and stop signal lamp. D4 goes to a fuse.

Finally, approximately how much of a load does the flasher need to see
before it will open the circuit and begin flashing?

Thanks for your reply.

Forgive me if this is an old post. My reader shows the date as 11/22/2013.

To answer the question, those lines on the switch mean that those contacts
are jumpered together.

To fix the problem, replace the turn signal flasher.

Nightcrawler® wrote:
"dave" wrote in message
m...
On 11/22/2013 01:00 AM, David Farber wrote:
This 1988 Plymouth Voyager has a flashing turn signal issue. When
either the left or right turn signal switch is engaged, the turn
signals light but do not flash. The hazard lights flash just fine.
Here is the wiring diagram:
http://webpages.charter.net/mrfixite...al-wiring1.jpg

At first one side of the turn signal lights were blinking but not
the other. Then, the working side went out too.The flasher was then
replaced (eBay) but that didn't help.

My question is what's the deal with the turn signal switch diagram
in the above linked picture? There are two, angled, thick black
lines located in the switch assembly (on the steering column).
Which part of the switch actually moves and which contacts get
connected? According to the continuity chart in the service manual, two
sets of
terminals get connected when the left signal is activated. The
first set connects terminals 4,7, and 8. The second set connects
terminals 9 and 10. For the right signal, the first set connects
terminals 5,7, and 9. The second set connects terminals 8 and 10.

In the neutral position, 8,9, and 10 are connected.

I checked continuity on all these terminals and they checked out
ok. By the way, not shown in the picture are where the wires, D7,
D6, D5, D8 and D4 terminate. Respectively, they terminate at the
right rear turn and stop signal lamp, D6 and D5 both go to the
front end lighting, and D8 goes to the left rear turn and stop
signal lamp. D4 goes to a fuse. Finally, approximately how much of a
load does the flasher need to
see before it will open the circuit and begin flashing?

Thanks for your reply.

Forgive me if this is an old post. My reader shows the date as
11/22/2013.
To answer the question, those lines on the switch mean that those
contacts are jumpered together.

To fix the problem, replace the turn signal flasher.

Thanks for the information abut the switch.

The flasher was replaced. It did not correct the problem.
--
David Farber
Los Osos, CA

David Farber wrote:
This 1988 Plymouth Voyager has a flashing turn signal issue. [...]
The flasher was then replaced (eBay) but that didn't help.

New, good, working flashers for that van are $6 + tax at the local auto
parts store. Counterfeit, used, and broken flashers have to cost more
than that on eBay with shipping. This car probably takes a 552 flasher.

For testing, the turn signal flasher can be replaced with a short piece
of 18 gauge wire (or thicker, like 16 or 14 gauge) with 1/4" male
terminals crimped on the ends. This should make the turn signals on the
appropriate side light up steadily when the turn signal switch is
flicked that way. If this doesn't happen, the problem is not in the
flasher.

My question is what's the deal with the turn signal switch diagram in
the above linked picture?

The "arrows" actually move. The tail of the arrow stays attached to its
dot and the head of the arrow moves around. The switch is shown in the
neutral/off position.

As shown, D9 (brake light switch) connects to D7 (right rear stop/turn)
and D8 (left rear stop/turn). D2 (turn signal flasher) isn't connected
to anything.

When you turn right, the little arrows all move up in parallel (as
shown by the dashed line). D9 (brake) is no longer connected to D7
(right rear stop/turn). D9 (brake) is still connected to D8 (left rear
stop/turn). D2 (turn) is connected to D7 (right rear stop/turn), so the
right rear light flashes. D2 is also connected to D5 (right front
turn), so the right front light flashes.

When you turn left, the little arrows all move down in parallel (as
shown by the dashed line). D9 (brake) is no longer connected to D8
(left rear stop/turn). D9 (brake) is still connected to D7 (right rear
stop/turn). D2 (turn) is connected to D8 (left rear stop/turn), so the
left rear light flashes. D2 is also connected to D6 (left front
turn), so the left front light flashes.

Finally, approximately how much of a load does the flasher need to
see before it will open the circuit and begin flashing?

Usually, one turn signal lamp, which is about 2 amps. One amp may or
may not do it, or it may take a *long* time to start flashing. Less
than one amp usually won't make it flash.

Matt Roberds

David Farber wrote:

Nightcrawler® wrote:

To fix the problem, replace the turn signal flasher.

Thanks for the information abut the switch.

The flasher was replaced. It did not correct the problem.
Have you changed any bulbs lately? The combined parking
light/turn-brake signal bulbs are polarized. The bayonet
pegs on the side are not directly across from each other.
When the lamp holders are worn a bit, you can put the bulbs
in backwards, exchanging the parking filament for the brake
light filament. The parking filament runs way less current,
and isn't enough for the flasher to work reliably (or at
all). Also, check if the flasher works some of the time,
related to whether the headlights are on/off. If it
only flashes when the headlights are OFF, then the ground
to the rear lights has gone open. The turn/brake circuit
then has to complete through both sets of filaments, again
lowering current that the flasher sees.

Some cars of that period also had some wonky wiring so that
the side marker lights would flash for turns and light steady
while headlights were on.

Some later cars have computer-controlled turn signals so you
get a fast flash for lane change indication, but that wouldn't
be on an '88.

Jon

Jon Elson wrote:
David Farber wrote:

Nightcrawler wrote:

To fix the problem, replace the turn signal flasher.

Thanks for the information abut the switch.

The flasher was replaced. It did not correct the problem.
Have you changed any bulbs lately? The combined parking
light/turn-brake signal bulbs are polarized. The bayonet
pegs on the side are not directly across from each other.
When the lamp holders are worn a bit, you can put the bulbs
in backwards, exchanging the parking filament for the brake
light filament. The parking filament runs way less current,
and isn't enough for the flasher to work reliably (or at
all). Also, check if the flasher works some of the time,
related to whether the headlights are on/off. If it
only flashes when the headlights are OFF, then the ground
to the rear lights has gone open. The turn/brake circuit
then has to complete through both sets of filaments, again
lowering current that the flasher sees.

Some cars of that period also had some wonky wiring so that
the side marker lights would flash for turns and light steady
while headlights were on.

Some later cars have computer-controlled turn signals so you
get a fast flash for lane change indication, but that wouldn't
be on an '88.

Jon

Hi Jon,

After the flasher replacement didn't work, all the bulbs that are in the
turn signal circuit were replaced, I think. There were other people working
on the car at the time. All the correct lights come on brightly when the
turn signal is activated. But you're absolutely correct that the lamp
sockets aren't in great shape and it is possible the dual filament bulbs
could be reversed. One of the front bulbs has a very poor looking socket and
won't illuminate all the time. However, I just tested the flasher on my
bench. It's a Wagner 323. The print on the cover says, "3 lamp 12 Volt,"
whatever that means. (How about a current rating?) I hooked a 4 ohm load and
cranked the voltage up to 12, the switch didn't open. Even going up to 16
volts which produced 4 amps of current didn't activate the flasher. There
was even a second flasher that came in the package, it didn't work on my
bench either.

Thanks for your reply.
--
David Farber
Los Osos, CA

wrote:
David Farber wrote:
This 1988 Plymouth Voyager has a flashing turn signal issue. [...]
The flasher was then replaced (eBay) but that didn't help.

New, good, working flashers for that van are $6 + tax at the local
auto parts store. Counterfeit, used, and broken flashers have to
cost more than that on eBay with shipping. This car probably takes a
552 flasher.

For testing, the turn signal flasher can be replaced with a short
piece of 18 gauge wire (or thicker, like 16 or 14 gauge) with 1/4"
male terminals crimped on the ends. This should make the turn
signals on the appropriate side light up steadily when the turn
signal switch is flicked that way. If this doesn't happen, the
problem is not in the flasher.

My question is what's the deal with the turn signal switch diagram in
the above linked picture?

The "arrows" actually move. The tail of the arrow stays attached to
its dot and the head of the arrow moves around. The switch is shown
in the neutral/off position.

As shown, D9 (brake light switch) connects to D7 (right rear
stop/turn) and D8 (left rear stop/turn). D2 (turn signal flasher)
isn't connected to anything.

When you turn right, the little arrows all move up in parallel (as
shown by the dashed line). D9 (brake) is no longer connected to D7
(right rear stop/turn). D9 (brake) is still connected to D8 (left
rear stop/turn). D2 (turn) is connected to D7 (right rear
stop/turn), so the right rear light flashes. D2 is also connected to
D5 (right front turn), so the right front light flashes.

When you turn left, the little arrows all move down in parallel (as
shown by the dashed line). D9 (brake) is no longer connected to D8
(left rear stop/turn). D9 (brake) is still connected to D7 (right
rear stop/turn). D2 (turn) is connected to D8 (left rear stop/turn),
so the left rear light flashes. D2 is also connected to D6 (left
front
turn), so the left front light flashes.

Finally, approximately how much of a load does the flasher need to
see before it will open the circuit and begin flashing?

Usually, one turn signal lamp, which is about 2 amps. One amp may or
may not do it, or it may take a *long* time to start flashing. Less
than one amp usually won't make it flash.

Matt Roberds

Hi Matt,

I should have included in my initial summary that the flasher replacement is
a Wagoner 323, 3 lamp, 12 volt device. I hooked it up on my bench,
increasing the voltage to as high as 16 volts to produce 4 amps of current.
It still did not open the circuit. Very curious or very bad right out of the
box.

Thanks for your reply.
--
David Farber
Los Osos, CA

David Farber wrote:
I should have included in my initial summary that the flasher
replacement is a Wagoner 323, 3 lamp, 12 volt device.

This is a fixed load flasher for 3 lamps of 32 candlepower each (lamps
like 1156, 1157, 2057). Its rated current is 6.4 A. (I have an older
Wagner paper catalog.)

Depending on how many lamps it has to flash, a 224 (2 lamp, 4.4 A), 228
(2 lamp, 4.75 A), or 322 (3 lamp, 5.3 A) flasher may also be a good
replacement.

Some auto parts stores only stock variable load flashers. If so, a 536
(1 to 6 lamp), 552 (1 to 6 lamp), or 575 (1 to 8 lamp) may be a good
replacement, but the 536 may be too tall to fit.

I hooked it up on my bench, increasing the voltage to as high as 16
volts to produce 4 amps of current. It still did not open the
circuit.

The catalog I have implies that if one lamp fails, a fixed load flasher
will stop flashing. This implies that it should flash with a load from
6.4 down to about 4.3 A. If you can load it to 6 A and it still doesn't
flash, I think it's probably bad.

If it does start flashing, check the lamps and lamp sockets, as has been
suggested. If the sockets are really beat, some car parts stores carry
replacement sockets; look carefully at the part that twists into the
reflector to make sure it's the same. The Chrysler dealer may or may
not still have them. A junkyard will have them but theirs are likely to
be beat up as well; the man at the desk should have an interchange book
that says what years are the same - try to get one from the newest year
you can.

Matt Roberds

wrote:
David Farber wrote:
I should have included in my initial summary that the flasher
replacement is a Wagoner 323, 3 lamp, 12 volt device.

This is a fixed load flasher for 3 lamps of 32 candlepower each (lamps
like 1156, 1157, 2057). Its rated current is 6.4 A. (I have an older
Wagner paper catalog.)

Depending on how many lamps it has to flash, a 224 (2 lamp, 4.4 A),
228 (2 lamp, 4.75 A), or 322 (3 lamp, 5.3 A) flasher may also be a
good replacement.

Some auto parts stores only stock variable load flashers. If so, a
536 (1 to 6 lamp), 552 (1 to 6 lamp), or 575 (1 to 8 lamp) may be a
good replacement, but the 536 may be too tall to fit.

I hooked it up on my bench, increasing the voltage to as high as 16
volts to produce 4 amps of current. It still did not open the
circuit.

The catalog I have implies that if one lamp fails, a fixed load
flasher will stop flashing. This implies that it should flash with a
load from
6.4 down to about 4.3 A. If you can load it to 6 A and it still
doesn't flash, I think it's probably bad.

If it does start flashing, check the lamps and lamp sockets, as has
been suggested. If the sockets are really beat, some car parts
stores carry replacement sockets; look carefully at the part that
twists into the reflector to make sure it's the same. The Chrysler
dealer may or may not still have them. A junkyard will have them but
theirs are likely to be beat up as well; the man at the desk should
have an interchange book that says what years are the same - try to
get one from the newest year you can.

Matt Roberds

Hi Matt,

This time, I increased the load from 4 ohms to about 2 ohms. The flasher
came on at a "normal" speed when the voltage was increased and the current
came up to about 5.5 amps. So now I have to check the change in the car
battery current when activating the turn signal and see if it's close to
this magic number.

Thanks so much for your help.

--
David Farber
Los Osos, CA

wrote:
David Farber wrote:
I should have included in my initial summary that the flasher
replacement is a Wagoner 323, 3 lamp, 12 volt device.

This is a fixed load flasher for 3 lamps of 32 candlepower each (lamps
like 1156, 1157, 2057). Its rated current is 6.4 A. (I have an older
Wagner paper catalog.)

Depending on how many lamps it has to flash, a 224 (2 lamp, 4.4 A),
228 (2 lamp, 4.75 A), or 322 (3 lamp, 5.3 A) flasher may also be a
good replacement.

Some auto parts stores only stock variable load flashers. If so, a
536 (1 to 6 lamp), 552 (1 to 6 lamp), or 575 (1 to 8 lamp) may be a
good replacement, but the 536 may be too tall to fit.

I hooked it up on my bench, increasing the voltage to as high as 16
volts to produce 4 amps of current. It still did not open the
circuit.

The catalog I have implies that if one lamp fails, a fixed load
flasher will stop flashing. This implies that it should flash with a
load from
6.4 down to about 4.3 A. If you can load it to 6 A and it still
doesn't flash, I think it's probably bad.

If it does start flashing, check the lamps and lamp sockets, as has
been suggested. If the sockets are really beat, some car parts
stores carry replacement sockets; look carefully at the part that
twists into the reflector to make sure it's the same. The Chrysler
dealer may or may not still have them. A junkyard will have them but
theirs are likely to be beat up as well; the man at the desk should
have an interchange book that says what years are the same - try to
get one from the newest year you can.

Matt Roberds

Hi Matt,

A couple more questions, for this simple kind of bi-metallic flasher, what
design differences are there between a variable load flasher and a fixed
load flasher? What would be the advantages to using a fixed load flasher?

From my observations, there are three dual element bulbs in the flashing
circuit and each one of them will draw 2.1 amps on the larger filament. Then
there is a smaller corner bulb that draws only 0.27 amps. That adds up to
6.57 amps. Am I correct in saying that the larger, higher current filaments
are assigned to the flashing circuit?

Thanks for your reply.
--
David Farber
Los Osos, CA

David Farber wrote:
A couple more questions, for this simple kind of bi-metallic flasher,
what design differences are there between a variable load flasher and
a fixed load flasher?

A fixed load flasher starts out closed (on), and the bimetal heats
itself up from the current drawn by the lamps. Once enough current has
been drawn for long enough, the bimetal snaps open (off), cools down,
snaps closed again (on), and so forth. It depends on the lamps drawing
enough current to heat the bimetal enough to start flashing.

A variable load flasher starts out open (off), and has a heating
element in parallel with the bimetal. Any path to ground will run the
heating element, and the bimetal will eventually snap closed (on).
This shorts out the heater, the bimetal cools down, snaps open (off),
and so forth.

What would be the advantages to using a fixed load flasher?

If one lamp fails with a fixed load flasher, the driver can tell that
there is a problem, because the remaining turn signal lamps will just
come on steady. Also, the lamps that do work will provide at least
some indication to other drivers.

The hazard (4-way) flasher is usually a variable load flasher, because
it should flash no matter what; if the car has just been in a wreck and
some of the turn signal lamps are smashed, it can still be useful to
flash the remaining turn signal lamps as a warning to other drivers.

Am I correct in saying that the larger, higher current filaments are
assigned to the flashing circuit?

Yep. The "bright" filament is always on the turn (or stop) circuit,
and the "dim" filament is always on the parking/running light circuit.

Thanks for your reply.

You're welcome!

Matt Roberds

wrote:
David Farber wrote:
A couple more questions, for this simple kind of bi-metallic flasher,
what design differences are there between a variable load flasher and
a fixed load flasher?

A fixed load flasher starts out closed (on), and the bimetal heats
itself up from the current drawn by the lamps. Once enough current
has been drawn for long enough, the bimetal snaps open (off), cools
down, snaps closed again (on), and so forth. It depends on the lamps
drawing enough current to heat the bimetal enough to start flashing.

A variable load flasher starts out open (off), and has a heating
element in parallel with the bimetal. Any path to ground will run the
heating element, and the bimetal will eventually snap closed (on).
This shorts out the heater, the bimetal cools down, snaps open (off),
and so forth.

What would be the advantages to using a fixed load flasher?

If one lamp fails with a fixed load flasher, the driver can tell that
there is a problem, because the remaining turn signal lamps will just
come on steady. Also, the lamps that do work will provide at least
some indication to other drivers.

The hazard (4-way) flasher is usually a variable load flasher, because
it should flash no matter what; if the car has just been in a wreck
and some of the turn signal lamps are smashed, it can still be useful
to flash the remaining turn signal lamps as a warning to other
drivers.

Am I correct in saying that the larger, higher current filaments are
assigned to the flashing circuit?

Yep. The "bright" filament is always on the turn (or stop) circuit,
and the "dim" filament is always on the parking/running light circuit.

Thanks for your reply.

You're welcome!

Matt Roberds

Hi Matt,

I visited the car this afternoon and measured the current difference between
turn signals on and off. It was less than 4 amps difference. I started
pulling the lamps and looked into the sockets. Both front left sockets were
covered in a green chalky substance. I guess that would explain the problem
there. On the right side, one of the two signal lights glowed brighter than
the other. Also, the bulb numbers were different. I should have checked that
first time around. The voltage at the dim bulb socket with no load was 1
volt less (11v vs. 12v) than the battery voltage. Another bad socket?
Checking the rear lights I noticed that the smaller filaments were glowing
when the turn signals were activated. I checked the socket and bulb and it
didn't seem possible that the bulb could have been inserted so that the
terminals were reversed. I had another appointment to go to so I couldn't do
anymore investigating but the first thing on the to do list will be to
replace the corroded sockets.

Thanks for your assistance.
--
David Farber
Los Osos, CA

On Mon, 25 Nov 2013 23:04:47 -0800, "David Farber"
wrote:

wrote:
David Farber wrote:
A couple more questions, for this simple kind of bi-metallic flasher,
what design differences are there between a variable load flasher and
a fixed load flasher?

A fixed load flasher starts out closed (on), and the bimetal heats
itself up from the current drawn by the lamps. Once enough current
has been drawn for long enough, the bimetal snaps open (off), cools
down, snaps closed again (on), and so forth. It depends on the lamps
drawing enough current to heat the bimetal enough to start flashing.

A variable load flasher starts out open (off), and has a heating
element in parallel with the bimetal. Any path to ground will run the
heating element, and the bimetal will eventually snap closed (on).
This shorts out the heater, the bimetal cools down, snaps open (off),
and so forth.

What would be the advantages to using a fixed load flasher?

If one lamp fails with a fixed load flasher, the driver can tell that
there is a problem, because the remaining turn signal lamps will just
come on steady. Also, the lamps that do work will provide at least
some indication to other drivers.

The hazard (4-way) flasher is usually a variable load flasher, because
it should flash no matter what; if the car has just been in a wreck
and some of the turn signal lamps are smashed, it can still be useful
to flash the remaining turn signal lamps as a warning to other
drivers.

Am I correct in saying that the larger, higher current filaments are
assigned to the flashing circuit?

Yep. The "bright" filament is always on the turn (or stop) circuit,
and the "dim" filament is always on the parking/running light circuit.

Thanks for your reply.

You're welcome!

Matt Roberds

Hi Matt,

I visited the car this afternoon and measured the current difference between
turn signals on and off. It was less than 4 amps difference. I started
pulling the lamps and looked into the sockets. Both front left sockets were
covered in a green chalky substance. I guess that would explain the problem
there. On the right side, one of the two signal lights glowed brighter than
the other. Also, the bulb numbers were different. I should have checked that
first time around. The voltage at the dim bulb socket with no load was 1
volt less (11v vs. 12v) than the battery voltage. Another bad socket?
Checking the rear lights I noticed that the smaller filaments were glowing
when the turn signals were activated. I checked the socket and bulb and it
didn't seem possible that the bulb could have been inserted so that the
terminals were reversed. I had another appointment to go to so I couldn't do
anymore investigating but the first thing on the to do list will be to
replace the corroded sockets.

Thanks for your assistance.
Greetings David,
As others have posted here you may have bad grounds. I have
experienced this myself. To reiterate, on some cars if the ground
connection is either missing or the resistance is very high the
current for the turn signal and brake filament will instead go to
ground through the tail light filament circuit. You have probably seen
cars with the taillights on and then when the car brakes one brake
light will be lit while on the other side the brake light and the tail
light are both unlit. Then when the brakes are released the one
working brake light goes out and both tail lights will be lit. A good
way to check this is to run a wire from a known good ground to the
brass base of the bulb, making sure the wire is making good contact
with the brass base. If the bulb starts flashing then you know the
ground is the problem and you can search for the exact place where it
is making a poor connection. The last time this happened to me the bad
ground was where the ground wire was connected to the tail lamp
assembly. There was an eye on the end of the ground wire and this eye
had a screw going through it. When I removed the screw there was
corrosion under the screw head and on both sides of the eye. I cleaned
off the corrosion, coated the eye with dielctric grease, reassembled
everything and put a little more grease over the eye, and now the
lights work.
Eric

wrote:
On Mon, 25 Nov 2013 23:04:47 -0800, "David Farber"
wrote:

wrote:
David Farber wrote:
A couple more questions, for this simple kind of bi-metallic
flasher, what design differences are there between a variable load
flasher and a fixed load flasher?

A fixed load flasher starts out closed (on), and the bimetal heats
itself up from the current drawn by the lamps. Once enough current
has been drawn for long enough, the bimetal snaps open (off), cools
down, snaps closed again (on), and so forth. It depends on the
lamps drawing enough current to heat the bimetal enough to start
flashing.

A variable load flasher starts out open (off), and has a heating
element in parallel with the bimetal. Any path to ground will run
the heating element, and the bimetal will eventually snap closed
(on). This shorts out the heater, the bimetal cools down, snaps
open (off), and so forth.

What would be the advantages to using a fixed load flasher?

If one lamp fails with a fixed load flasher, the driver can tell
that there is a problem, because the remaining turn signal lamps
will just come on steady. Also, the lamps that do work will
provide at least some indication to other drivers.

The hazard (4-way) flasher is usually a variable load flasher,
because it should flash no matter what; if the car has just been in
a wreck and some of the turn signal lamps are smashed, it can still
be useful to flash the remaining turn signal lamps as a warning to
other drivers.

Am I correct in saying that the larger, higher current filaments
are assigned to the flashing circuit?

Yep. The "bright" filament is always on the turn (or stop) circuit,
and the "dim" filament is always on the parking/running light
circuit.

Thanks for your reply.

You're welcome!

Matt Roberds

Hi Matt,

I visited the car this afternoon and measured the current difference
between turn signals on and off. It was less than 4 amps difference.
I started pulling the lamps and looked into the sockets. Both front
left sockets were covered in a green chalky substance. I guess that
would explain the problem there. On the right side, one of the two
signal lights glowed brighter than the other. Also, the bulb numbers
were different. I should have checked that first time around. The
voltage at the dim bulb socket with no load was 1 volt less (11v vs.
12v) than the battery voltage. Another bad socket? Checking the rear
lights I noticed that the smaller filaments were glowing when the
turn signals were activated. I checked the socket and bulb and it
didn't seem possible that the bulb could have been inserted so that
the terminals were reversed. I had another appointment to go to so I
couldn't do anymore investigating but the first thing on the to do
list will be to replace the corroded sockets.

Thanks for your assistance.
Greetings David,
As others have posted here you may have bad grounds. I have
experienced this myself. To reiterate, on some cars if the ground
connection is either missing or the resistance is very high the
current for the turn signal and brake filament will instead go to
ground through the tail light filament circuit. You have probably seen
cars with the taillights on and then when the car brakes one brake
light will be lit while on the other side the brake light and the tail
light are both unlit. Then when the brakes are released the one
working brake light goes out and both tail lights will be lit. A good
way to check this is to run a wire from a known good ground to the
brass base of the bulb, making sure the wire is making good contact
with the brass base. If the bulb starts flashing then you know the
ground is the problem and you can search for the exact place where it
is making a poor connection. The last time this happened to me the bad
ground was where the ground wire was connected to the tail lamp
assembly. There was an eye on the end of the ground wire and this eye
had a screw going through it. When I removed the screw there was
corrosion under the screw head and on both sides of the eye. I cleaned
off the corrosion, coated the eye with dielctric grease, reassembled
everything and put a little more grease over the eye, and now the
lights work.
Eric

Hi Eric,

Agreed, weird things happen when grounds open up and other circuit paths get
involved. If I had more time, I'd trace each lamp circuit individually which
is probably what I'll have to do anyway.

Thanks for your reply.
--
David Farber
Los Osos, CA

David Farber wrote:
After replacing three of the four front turn signal sockets today,
all is well again.

Thanks for posting back with what fixed it!

Matt Roberds