Does anyone have a wiring diagram for converting an old tractor wiring
system from 6v (dynamo) to 12v (alternator)?
Thanks

cmackay wrote:
Does anyone have a wiring diagram for converting an old tractor wiring
system from 6v (dynamo) to 12v (alternator)?

Boy, are you in the wrong forum. IIR anything, the positive becomes
negative to start with and then you have a big deal with the earth
wires.

There was also something about heat sinks and rectifiers -or was that
just the good old days?

In article . com,
Weatherlawyer says...

cmackay wrote:
Does anyone have a wiring diagram for converting an old tractor wiring
system from 6v (dynamo) to 12v (alternator)?

Boy, are you in the wrong forum.

Is he hell. It's something commonly done to classic cars, especially
Morris Minors.

IIR anything, the positive becomes
negative to start with and then you have a big deal with the earth
wires.

No you don't. You don't understand electrics at all do you?

--
Conor,

Same ****, different day.

Conor wrote:
In article . com,
Weatherlawyer says...

Boy, are you in the wrong forum.

Is he hell. It's something commonly done to classic cars, especially Morris Minors.

That's why I reposted it from UK.d-i-y.

IIR anything, the positive becomes negative to start with and then you have a big
deal with the earth wires.

No you don't. You don't understand electrics at all do you?

If I ever did, it was a long time before these things became classics.
And You are right, I don't remember much about it -but then it was an
awful long time ago.

So long ago I don't recall the name of the voltage control doo dah that
was the last thing I ever messed with on one of those things from the
pre alternator days.

That's why I reposted it to uk.rec.cars.classic. You dip****!

*******

Is there anyone here that actually has an answer for the OP?

Dead easy but I can't draw it out here.
Most alternators have 3 terminals. The BIG one is obvious and goes to
battery +.
The sense terminal also goes to battery +. The two are seperate so that
the sense senses battery voltage regardless of the volt drop on the big
wire. However, for a tractor, they can be simply comnnected at the
aternator.
The ign terminal connects to the ignition through a warning light,
typically 2.2W.
You will need to change the battery to negative earth. The ignition
coil and the bulbs will need changing but the 6V starter will be OK. It
will crank quickly but won't overheat unless you are stupid and crank
for ages. Glow plugs will also need changing if it's diesel. If the
thing is 6V, it's so old there's not much more to worry about.
My Ferguson T20 is converted to 12V and there's no problem.

John

Weatherlawyer wrote:

Conor wrote:

In article . com,
Weatherlawyer says...


Boy, are you in the wrong forum.


Is he hell. It's something commonly done to classic cars, especially Morris Minors.


That's why I reposted it from UK.d-i-y.


IIR anything, the positive becomes negative to start with and then you have a big
deal with the earth wires.


No you don't. You don't understand electrics at all do you?


If I ever did, it was a long time before these things became classics.
And You are right, I don't remember much about it -but then it was an
awful long time ago.

So long ago I don't recall the name of the voltage control doo dah that
was the last thing I ever messed with on one of those things from the
pre alternator days.

That's why I reposted it to uk.rec.cars.classic. You dip****!

*******

Is there anyone here that actually has an answer for the OP?


When you fit an alternator - basically most alternators have a built in
regulator so the output goes to the positive of the battery. You may
have to fit into the circuit a indicator lamp (low watts)which comes
from a live pos feed and goes to the alternator small terminal - this is
the excite the diodes in the alternator to make it work. (this also is
dependent on the make of alternator)

So all wires are from the pos terminal of the battery. The old voltage
regulator removed - wires are soldered together.

Hope this makes sense!

On 14 Feb 2006 06:05:32 -0800, "cmackay"
wrote:

Does anyone have a wiring diagram for converting an old tractor wiring
system from 6v (dynamo) to 12v (alternator)?

Charity shop, get a Haynes manual for anything '70s - preferably
something with the same maker of alternator. Just copy it.

Lucas alternators are rubbish. Fit a Bosch. Japanese alternators are
great, but not weatherproof.

It'll be negative earth afterwards and it might have been positive earth
beforehand. If you replace both battery and dynamo/alternator together
then you've sorted it out anyway. Ammeters and voltmeters might care
too, other gauges generally won't.

Alternators come in two sorts - regulators inside, or separate
regulators. Nearly all of them outside the USA are external. The
installation difference is trivial (one extra wire). Regulators aren't
interchangeable, so keep the one that came with the alternator. Replace
the wire between alternator output and battery with something suitably
heavy (recycled from the donor car might work, if long enough).

Wire the charge warning light according to the alternator circuit and
use the right bulb. If it's an old Lucas ACR alternator, then this bulb
is a crucial part of the circuit and _must_ be the right rating!
(usually in a red holder in the dashboard, not black or white like the
rest).

Discard any ammeter. Add a voltmeter if you wish (more use with an
alternator).

Electronic rev counters (which I doubt you have, unless it's a Yank)
need replacement.

All bulbs change to 12V, as does the indicator flasher (if fitted).

Dashboard fuel / temp gauge might need replacement, or else a solid
state regulator (a 7905 and a couple of resistors, AFAIR) added to its
existing voltage regulator.

The ignition coil should be replaced, which is probably a good thing
anyway. Don't use a ballasted coil where there's a resistor in the feed
to it (or a Ford coil).

Diesel pre-heaters can be left alone, but don't leave them on too long.
Replace them with 12V if you do break them.

The starter can stay, but you might change its solenoid (it may not even
have one on a tractor, and I assume it's a helix not a pre-engaged
starter). Or else just ignore it and fix it if you break it. Ford used
to be the easiest source for a separate solenoid, as they kept using
them for longest.

Vehicle Wiring Products (webbable) are your best source for parts. Get a
decent crimp tool for non-insulated crimps and don't use the
pre-insulated sort if you care about reliability. Some silicone grease
too.


--
Cats have nine lives, which is why they rarely post to Usenet.

On 14 Feb 2006 06:21:20 -0800, "Weatherlawyer"
wrote:

Boy, are you in the wrong forum.

Have you sobered up yet from the other night?

In article ,
Andy Dingley wrote:
Lucas alternators are rubbish. Fit a Bosch.

They're often identical from the '80s.

--
*If all is not lost, where the hell is it?

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 15 Feb 2006 01:20:39 +0000 (GMT), "Dave Plowman (News)"
wrote:

In article ,
Andy Dingley wrote:
Lucas alternators are rubbish. Fit a Bosch.

They're often identical from the '80s.

Basically, avoid the old Lucas designs (especially the ubiquitous ACR).
The more recent stuff was nothing like as badly designed.

Bosch build quality was rubbish when they were supplying it to Rover.
There was an attitude that "the Brits would accept anything" that they'd
never have tried on with VW. Alternators weren't too bad, but the
starter solenoids were ghastly (I did one of the test rigs). As for the
actual factory location for stuff from the '90s it's pretty hard to
tell, but generally anything that looks like Lucas was obsolete and
anything that looks like Bosch was well-intentioned but shoddy.

In article ,
Andy Dingley wrote:
Basically, avoid the old Lucas designs (especially the ubiquitous ACR).
The more recent stuff was nothing like as badly designed.

The ACR fitted to my old P6 Rover simply didn't work as intended. It
claimed to be 45 amps output but couldn't even balance a 40 amp load. I
ended up designing a new regulator (based on an earlier Lucas design) and
fitting it eternally. Had a pot to set the output voltage. No more
problems after that.

The 70 amp one fitted to my SD1 is ok though and has lasted well. It's one
of the ones which could be either Bosch or Lucas and they appear identical.

--
*If vegetable oil comes from vegetables, where does baby oil come from? *

Dave Plowman London SW
To e-mail, change noise into sound.

Conor wrote:
In article . com,
Weatherlawyer says...

cmackay wrote:
Does anyone have a wiring diagram for converting an old tractor wiring
system from 6v (dynamo) to 12v (alternator)?

Boy, are you in the wrong forum.

Is he hell. It's something commonly done to classic cars, especially
Morris Minors.


Did they used to be 6v?? My Mini Minor had a dynamo but it was 12v
(pos earth)

Andy Dingley wrote:
Lucas alternators are rubbish. Fit a Bosch. Japanese alternators are
great, but not weatherproof.

Gosh, that'll make Japanese cars very unreliable, then.

Dave Plowman (News) wrote:
I
ended up designing a new regulator (based on an earlier Lucas design) and
fitting it _eternally_.

That would be due to the loose nut involved in the installation then?

Rover cars are like Victorian pine floors.

Most people simply throw them away, but there is always someone
somewhere who thinks that spending more man hours on them than were ever
spent on their original construction will turn a sows ear into a
lambswool mitten...

Andy Dingley wrote:

Have you sobered up yet from the other night?

Remind me. It must have been a good one.

In article .com,
wrote:
Is he hell. It's something commonly done to classic cars, especially
Morris Minors.


Did they used to be 6v?? My Mini Minor had a dynamo but it was 12v
(pos earth)

Morris changed to 12 volts before WW2. Think some Fords and VW were about
the only ones to use 6 volts post war.

--
*A bartender is just a pharmacist with a limited inventory *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
The Natural Philosopher wrote:
I
ended up designing a new regulator (based on an earlier Lucas design) and
fitting it _eternally_.

That would be due to the loose nut involved in the installation then?

Bleeding spool cheekers. ;_)

Rover cars are like Victorian pine floors.

Most people simply throw them away, but there is always someone
somewhere who thinks that spending more man hours on them than were ever
spent on their original construction will turn a sows ear into a
lambswool mitten...

I had sucessively two different models of the P6 - both 3500, but one
manual and one auto over about 15 years and they were little trouble.

The SD1 is simply fun to drive. ;-)

--
*When I'm not in my right mind, my left mind gets pretty crowded *

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 15 Feb 2006 11:32:14 +0000, Chris Bacon
wrote:

Andy Dingley wrote:
Lucas alternators are rubbish. Fit a Bosch. Japanese alternators are
great, but not weatherproof.

Gosh, that'll make Japanese cars very unreliable, then.

Japanese cars have a bonnet. Tractors don't.

Their alternators are small and have high outputs, on account of good
cooling airflow. However the open ended cases that permit the airflow
also let rain in.

If you have a Tonka toy 4x4 and you get it wet, then alternator problems
are likely, in a way that rarely arises with Landies.