Changing from 6 to 12 volts

[tallyho8]

A friend bought a 1941 Model M Farmall 3 wheeler that a neighbor had and he is trying to fix it up. I have noticed some 12 volt changeover kits for sale and they come with an alternator but not a starter. Can you use 12 volts on a 6 volt starter without burning it up?

 

[RickB]

A reasonably healthy 6 volt starter will get by very well on a 12 volt diet. Convert if you want to, and leave the starter alone until it requires attention. It could last for years.

 

[ultrarunner]

A lot of the Ford guys leave the Starter as is... sometimes it's a little harder on the Bendix Drive... the armature and field coils don't seem to have a problem.

 

[Travelover]

Another option is to use two 6 volt batteries in series. Charge 12 v across both batteries, run 6 volt needs off "first" 6 v battery.

Used to use this set up for 12 volt Corvair engine in 6 volt VW bug back in the day.

 

[ToadHill]

If my old memory serves me right, DC motors don't care if it runs on 6,12,18,24 volts. If the insulation is good, they just spin faster with more volts.

 

[elad]

Better than 15 years ago, I up graded a 1953 Super C Farmall
to 12 volt. Used Chevy. alternator with internal regulator. Had to make
some brackets etc. and use a double V pulley to drive it. Never had a
single problem with the change over. The starter is still the original
6 volt unit. Only thing ever replaced was the battery 2 or 3 times.
elad

 

[Kaliburz]

There should be no issue.

At one time, JC Whitney actually sold a 6 Volt alternator. I used on an old Farmall that I didn't want to do a full change over (had to make it negative ground.)

Make sure you remember to check the ground of the battery. I think the older tractors were a six volt POSITIVE ground. So you'll have to swap the AMP guage connections, swap the coil and connections, etc, etc.....

 

[Soundguy]

I'd also leave the 6v starter as Rick and the others said. I've got plenty of fords with 6v starters and 12v 'kits'.

Big copper in a 6v starter.

soundguy

 

[thl]

I switched my 1943 2N from 6 to 12 volts many years ago. As Soundguy points out, the 6 volt starter will work just fine. I have had no problems.

Terry

 

[MikeD74T]

tallyho8, You don't mention whether the M has lights. If so the bulbs will need to be changed. Also my memory is a little vague but I recall that the 6 volt voltage regulator is in the pod that has the light & ignition switches ???? You may need to eliminate that circuit ?? MikeD74T

 

[StickMan]

As several have pointed out, starter should be fine, but as Mike states, don't forget about lights.

I converted a Ford 8N from 6 to 12 and everything worked fine. The lights even worked for about 1.2 seconds (really bright, then really dark). Switched them over to 12v, and all was good.

One other thing I did was to replace the ammeter with a voltmeter. When I would start the tractor, the voltmeter showed 12v. Cranking up the RPMs got it to jump up to around 14 - where I thought it should be. Only once had to jump the terminals to reenergize it when it wouldn't start charging on its own.

Eventually had to switch out the ignition switch, but that may have been related to age rather than the 6 to 12v conversion.

 

[Soundguy]

No good reason to switch to a volt meter, unless you don't understand what an ammeter is actually telling you about your electrical system. A battery with a bad cell may require constant high charge rate. your volt meter will happilly show 14v while the machine is running, and then you shut her off and she won't start and volt meter shows low.. like 10v..(severly discharged ).. An ammeter ont e other hand would show you that NET high charge rate, letting you know you needed to fix something.

if I had to have a volt meter ( cuz that's what we have in our cars these days ), then I'dd add it and keep the ammeter. Also note.. that the votl meter is not a drop in replacement for the ammeter, as it sets int he circuit.. a volt meter is a parallel device.. the ammeter is a serial device.

As for needing to rev up to get the alternator charging.. sounds like a yucky 1-wire job.. the 3-wire units are way more prefered.. and will start to charge at a low 400rpm

soundguy