OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".

Have had issue on occasion w/ safety interlock on tranny, but that ain't
the problem this time; have tested continuity from switch connection
thru both safety contacts (transmission and blade) to connection at
solenoid and is good. Plus, when one of them fails to make contact,
won't crank but does get voltage to generator charge light; not getting
that far now.

Question -- is way to test if solenoid isn't operating might be issue?
Service manuals aren't online but here's a link to the parts diagram for
the wiring harness that is a fairly complete wiring layout.

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePa geServlet_Alt

I scanned the wiring diagram I have; don't know how good it'll be but
there's a copy posted here...

http://photobucket.com/userinfo/reset/dpb_bucket/9d06ddac9fcf93eb81b6e66ef293a072ecd6c948

Any troubleshooting help/suggestions appreciated...

--

On Jun 4, 2:52�pm, dpb wrote:
OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".

Have had issue on occasion w/ safety interlock on tranny, but that ain't
the problem this time; have tested continuity from switch connection
thru both safety contacts (transmission and blade) to connection at
solenoid and is good. �Plus, when one of them fails to make contact,
won't crank but does get voltage to generator charge light; not getting
that far now.

Question -- is way to test if solenoid isn't operating might be issue?
Service manuals aren't online but here's a link to the parts diagram for
the wiring harness that is a fairly complete wiring layout.

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view...

I scanned the wiring diagram I have; don't know how good it'll be but
there's a copy posted here...

http://photobucket.com/userinfo/reset/dpb_bucket/9d06ddac9fcf93eb81b6...

Any troubleshooting help/suggestions appreciated...

--

Knowing the engine type and model would help. Anyway, you should have
one wire coming from the magneto. This is nothing more than a kill
switch. Disconnect it. After disconnecting it, make sure it isn't
touching any metal. Then jump the solenoids 2 big wire lugs. This will
make the engine turn over and start (assuming there isn't other
issues). BUT! in order to stop it, you must ground that wire to the
engine/frame.

Hank

On Jun 4, 2:52�pm, dpb wrote:
OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".

Have had issue on occasion w/ safety interlock on tranny, but that ain't
the problem this time; have tested continuity from switch connection
thru both safety contacts (transmission and blade) to connection at
solenoid and is good. �Plus, when one of them fails to make contact,
won't crank but does get voltage to generator charge light; not getting
that far now.

Question -- is way to test if solenoid isn't operating might be issue?
Service manuals aren't online but here's a link to the parts diagram for
the wiring harness that is a fairly complete wiring layout.

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view...

I scanned the wiring diagram I have; don't know how good it'll be but
there's a copy posted here...

http://photobucket.com/userinfo/reset/dpb_bucket/9d06ddac9fcf93eb81b6...

Any troubleshooting help/suggestions appreciated...

--

I forgot to add...............if it starts after doing what I said,
you either have a bad ignition switch, bad solenoid, or a wiring/fuse
issue. I can't tell you which unless I know what kind of solenoid you,
then I could tell you how to test the solenoid.

Hank

Hank

Hustlin' Hank wrote:
....
Knowing the engine type and model would help. ...

Tecumseh HH100

--

In article , dpb wrote:

OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".

Have had issue on occasion w/ safety interlock on tranny, but that ain't
the problem this time; have tested continuity from switch connection
thru both safety contacts (transmission and blade) to connection at
solenoid and is good. Plus, when one of them fails to make contact,
won't crank but does get voltage to generator charge light; not getting
that far now.

Question -- is way to test if solenoid isn't operating might be issue?
Service manuals aren't online but here's a link to the parts diagram for
the wiring harness that is a fairly complete wiring layout.

http://jdpc.deere.com/jdpc/servlet/c...g.view.servlet
s.HomePageServlet_Alt

I scanned the wiring diagram I have; don't know how good it'll be but
there's a copy posted here...

http://photobucket.com/userinfo/rese...eb81b6e66ef293
a072ecd6c948

Any troubleshooting help/suggestions appreciated...

--

Neither of your links took me anywhere useful. The first link took me to
a model search page, the second link took me to a password reset page.

I don't quite understand this question. Can you rephrase it?

is way to test if solenoid isn't operating might be issue?

Are you asking how to test a solenoid, or whether a faulty solenoid
could cause the symptoms, or what?

On Jun 5, 1:37�am, Smitty Two wrote:

Neither of your links took me anywhere useful. The first link took me to
a model search page, the second link took me to a password reset page.

I don't quite understand this question. Can you rephrase it?

is way to test if solenoid isn't operating might be issue?

Are you asking how to test a solenoid, or whether a faulty solenoid
could cause the symptoms, or what?-

Testing a solenoid is pretty straight forward. I'll try to explain
it.......You will either have a 3 wire ( 2 big cable and 1 little
wire), or a 4 wire ( 2 big cables and 2 little ones). If it is a 3
wire.....the small wire should have 12 volts going to it when you turn
the ignition switch to START. The ground part is thru the bracket, so
make sure it is getting good contact to the frame/engine.
The four wire (probably the one you have)..........one of the small
wires will have 12v going to it when the key is turned to the START
position, or maybe a wire that runs form the battery/big cable, and
the other is going to ground via a series of safety switches. If you
ground that wire, the solenoid will activate and the engine will turn
over if the solenoid is good. Again, assuming there are not other
issues.

Hank

On Jun 5, 1:37*am, Smitty Two wrote:
In article , dpb wrote:
OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".

Have had issue on occasion w/ safety interlock on tranny, but that ain't
the problem this time; have tested continuity from switch connection
thru both safety contacts (transmission and blade) to connection at
solenoid and is good. *Plus, when one of them fails to make contact,
won't crank but does get voltage to generator charge light; not getting
that far now.

Question -- is way to test if solenoid isn't operating might be issue?
Service manuals aren't online but here's a link to the parts diagram for
the wiring harness that is a fairly complete wiring layout.

http://jdpc.deere.com/jdpc/servlet/c...tscatalog.view....
s.HomePageServlet_Alt

I scanned the wiring diagram I have; don't know how good it'll be but
there's a copy posted here...

http://photobucket.com/userinfo/rese...ac9fcf93eb81b6....
a072ecd6c948

Any troubleshooting help/suggestions appreciated...

--

Neither of your links took me anywhere useful. The first link took me to
a model search page, the second link took me to a password reset page.

I don't quite understand this question. Can you rephrase it?

is way to test if solenoid isn't operating might be issue?

Are you asking how to test a solenoid, or whether a faulty solenoid
could cause the symptoms, or what?

I don't understand exactly what's going on either. He posted:

"have tested continuity from switch connection
thru both safety contacts (transmission and blade) to connection at
solenoid and is good. "

Continuity is great, but is the solenoid getting 12V when the ignition
switch is moved to start? If it is and the solenoid won't engage,
then it's a bad solenoid, which can be verified by briefly hooking 12V
directly to it.

But that wouldn't seem to be the problem, given that the complaint was
there is no voltage getting to the entire ignition system. Should be
easy enough to trace back. If there is no 12V at the solenoid, then
find out if 12V is getting to the start switch.

Smitty Two wrote:
In article , dpb wrote:

OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".

....

Neither of your links took me anywhere useful. The first link took me to
a model search page, the second link took me to a password reset page.

My bad...sorry. Here's the correct link to the wiring diagram--worked
this time here, anyway...

http://i153.photobucket.com/albums/s228/dpb_bucket/483a843a.jpg

The JD link I tried earlier appears it only returns to the image when
the search servlet is open--this one appears to work directly to open
the image.

If you're of a mind to actually pursue, the model is a 112 and the
catalog section is 1027 - 112 & 112H (-100,000) Lawn & Garden Tractors..
The Electrical Section is 24 in Sectional index. Not terribly
significant other than it allows one to visualize the diagram more easily.

I don't quite understand this question. Can you rephrase it?

is way to test if solenoid isn't operating might be issue?

Are you asking how to test a solenoid, or whether a faulty solenoid
could cause the symptoms, or what?

Yes...

I'm not positive _what_ I'm asking, unfortunately. This case is
puzzling me in that it's different than anything I've run across before.
I have no power anywhere past the link from the battery +ive terminal
to the solenoid but I can not find any discontinuity in wiring, the
interlock safety switch circuit is functional, etc.

I've just not had any luck in figuring out what is going on.
Contributed to by the fact all the pieces are under the battery mounting
bracket behind the dash panel so it's exceedingly difficult to get to
points on regulator, etc., to even probe.

I was really hoping somebody else could see what I'm not about where
there _should_ be voltage when switch is "on" to aid in isolating why
there isn't anything.

At one point in the process the generator-charging light did come back
on again, but when I then tried to see if it would turn the starter, it
went dead again and haven't been able to get a flicker since. That
occurred when I was checking the transmission interlock switch that
occasionally has come loose or misadjusted so I thought I'd found it.
But, the symptoms are back and the interlock circuit tests for
continuity through both from one end to another so it's somewhere else.

Sorry I don't have a better handle on it; if I did I probably would have
already seen what I'm missing...

--

dpb wrote:
....
The JD link I tried earlier appears it only returns to the image when
the search servlet is open--this one appears to work directly to open
the image.
....
Sorry, forgot to paste it in after I got a direct link...

http://jdpc.deere.com/pimages/MP35/MP356__________UN02JAN94.gif

Note the safety interlock circuit doesn't show up on this wiring harness
parts diagram but is on the wiring diagram. I think the pieces-parts
are Section 22 for the tranny lock; the mower deck safety switch is
probably in the accessories/attachments w/ the deck altho I've not
looked. Not that I think that is important; I'm pretty sure that
portion is ok at this point.

--

On Jun 5, 10:17*am, dpb wrote:
dpb wrote:

... The JD link I tried earlier appears it only returns to the image when
the search servlet is open--this one appears to work directly to open
the image.

...
Sorry, forgot to paste it in after I got a direct link...

http://jdpc.deere.com/pimages/MP35/MP356__________UN02JAN94.gif

Note the safety interlock circuit doesn't show up on this wiring harness
parts diagram but is on the wiring diagram. *I think the pieces-parts
are Section 22 for the tranny lock; the mower deck safety switch is
probably in the accessories/attachments w/ the deck altho I've not
looked. *Not that I think that is important; I'm pretty sure that
portion is ok at this point.

--

Since you have no 12V anywhere, I'd focus on finding the lines to the
ignition switch. It only has 3 connections. One should be 12V hot
all the time. One other should be hot when switch is in run. Last
one should be hot when key is moved to start.

Since you have apparently verified that the interlock circuit has
continuity, that should not be the problem.

In article , dpb wrote:

Here's the correct link to the wiring diagram--worked
this time here, anyway...

http://i153.photobucket.com/albums/s228/dpb_bucket/483a843a.jpg

I could be wrong, but it looks to me that three switches are in series
with the solenoid coil. A fault in any one of them would prevent the
solenoid from operating.

Can you trace voltage (to hell with continuity) through the

1. voltage regulator
2. ignition switch
3. mower safety switch
4. neutral start switch?

dpb wrote:
OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".
....

Well, what a combination of coincidental stuff, particularly as happened
since last used at which time had no problems!!!

First off, rebuilt tranny early this spring and while had it apart took
the opportunity to clean up longterm effects of battery spills.
Apparently did not get the nut holding the jumper from the battery side
of the solenoid to the 'bat' terminal on the regulator tight so the
apparently the nut came off while it was running the last time and
simply contacting the stud kept it running while it was. When changed
out the battery (the old one had gotten to where it was no longer
holding charge) apparently I knocked it off completely--hence the "no
voltage" symptom. Given the location deep down under the battery cage
and fuel tank, it wasn't simple to see so missed it wasn't connected
early on. Anyway, one would think that replacing that would fix all,
wouldn't one? Well, ....

Did get ignition light, no kick. Back track, discover bad connection at
switch isn't making contact all the time. Clean contacts, test, all's well.

Put all back together (had to take tank, battery holder, etc., off to
get to switch contacts to check and clean them) and poof!!! no kick again.

Now, trace back to another dirty contact in the safety circuit that
while pulling on the wiring harness to fix the switch contacts caused to
now show up...

Pull apart again to get to it; retest...bingo!

This time, _FINALLY_ it cranks and runs...

Anyway, thanks for the input...

--

dpb wrote:
dpb wrote:
OK, I'm stumped...

JD 112H lawn tractor (nearly ancient)

Symptom is no voltage in ignition system when turn key to "on/start".
...

Well, what a combination of coincidental stuff, particularly as happened
since last used at which time had no problems!!!

First off, rebuilt tranny early this spring and while had it apart took
the opportunity to clean up longterm effects of battery spills.
Apparently did not get the nut holding the jumper from the battery side
of the solenoid to the 'bat' terminal on the regulator tight so the
apparently the nut came off while it was running the last time and
simply contacting the stud kept it running while it was. When changed
out the battery (the old one had gotten to where it was no longer
holding charge) apparently I knocked it off completely--hence the "no
voltage" symptom. Given the location deep down under the battery cage
and fuel tank, it wasn't simple to see so missed it wasn't connected
early on. Anyway, one would think that replacing that would fix all,
wouldn't one? Well, ....

Did get ignition light, no kick. Back track, discover bad connection at
switch isn't making contact all the time. Clean contacts, test, all's
well.

Put all back together (had to take tank, battery holder, etc., off to
get to switch contacts to check and clean them) and poof!!! no kick again.

Now, trace back to another dirty contact in the safety circuit that
while pulling on the wiring harness to fix the switch contacts caused to
now show up...

Pull apart again to get to it; retest...bingo!

This time, _FINALLY_ it cranks and runs...

Anyway, thanks for the input...

--
Hi,
Sudden death is easy to fix. Remember IBM motto? Think(logic)!
After thought. You did not mention tranny rebuilding after all!

Tony Hwang wrote:
....
... You did not mention tranny rebuilding after all!

POAD...

--