Voltage Issues in 450

Joel Wilson · Jul 13, 2012

I have an old Farmall 450, approximately 1956, with voltage issues. It was originally a 6 volt, now has a 12 volt battery, 12 volt generator, and a voltage resistor to the points in the distributor. I"ve recently burned up two resistors, one voltage regulator, and a set of points. With the old regulator, battery and resistor were getting 18 volts from generator. With the new regulator, the battery is only getting a modest 13 volts, but when I shut off the tractor, the battery discharges. Anyone got useful advice, short of replacing the generator and regulator with an alternator, or rewiring the whole tractor? Thanks.

mkirsch · Jul 13, 2012

Could be a faulty new regulator. The cheap Chinese regulators seem to only be about 75% reliable out of the box.

Hugh McKinney · Jul 13, 2012

Well, believe it or not, I had almost the exact same problem with my 1957 vintage 450, and I was absolutely stumped. What was it? The battery cable snakes its way from the negative post to the tunnel that goes forward (near your feet) through several other twists and turns. It looked like a perfectly okay battery terminal, even when carefully examined. I took it off, and put on a new one, the problem disappered and has never come back. Apparently the insulation in one spot was very thin, and it was able to discharge the battery overnight, against a ground somewhere (but I never found it). Change out that battery cable. Good luck!

Janicholson · Jul 13, 2012

I agree With mkirsch, The ""new regulator may be sticking closed on the cutout points. Those have a delicate adjustment, and often just a bent tab to make the adjustment.
Charge the battery with one terminal disconnected to assure it is getting fully charged. When fully charged:
Use a volt meter to check for voltage between the disconnected terminal and the battery post (with all switches shut off). Less than .15 volts (or nothing) is OK. If it reads 12v or a bit more, there is a direct draw-- like the cutout contacts are stuck closed--.
If you disconnect the Bat terminal from the regulator and keep it isolated, the draw might go to zero. If it does, the odds are it is the contacts.
If between .1 something and 12v, the draw should be traced by disconnecting one wire at a time to isolate the draw. (reconnect each if it does not reduce the draw.
13v Charging might be due to a partially discharged battery. Jim

pete 23 · Jul 13, 2012

Pretty easy to test to see if cutout staying closed. With engine just shut down, unhook the wire from gen arm terminal and see if it sparks, or put a test lamp on that terminal. If cutout is sticking it will fry that generator real fast along with the points in cut out. Way too many cutouts get blamed for some other problem. You can take the cover off regulator also, but, when doing that it may not test the same as it changed the magnetic field a little bit. Cut out should close at just a little over battery voltage, about 6.6 volts and open with just a few amps of reverse current flow when shut down or even idled down slow depending on generator etc.

FC Andy · Jul 13, 2012

I tend to think that 75% reliable is giving the Indian made ones I've dealt with in the last few years far too much credit. -Andy

Joel Wilson · Jul 14, 2012

Something else for me to try today. Thanks.

Joel Wilson · Jul 14, 2012

Yes. I am getting a little more than frustrated with available parts. Nothing ever comes with "Made in the USA" stamped on it.

Joel Wilson · Jul 14, 2012

Thanks for the advice. I now know what I am going to do today.

Voltage Issues in 450

Joel Wilson

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mkirsch

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Hugh McKinney

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Janicholson

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pete 23

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FC Andy

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Joel Wilson

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Joel Wilson

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Joel Wilson

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