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Short in a '53 M38A1

Hello,

I've got a rookie question for the veterans out there. I have a '53 M38A1 that runs very nicely except that I believe there is a short circuit somewhere causing the battery to drain after about 24 to 48 hours. To prevent this, I added a removable battery post screw which I take off when I park. This is a 24 volt system, it was not converted to 12V.

I have read a lot of posts detailing how to tell if you have a short and how to find out where it is. Each one I have read suggests attaching a multimeter to watch the amps / current or a test light and pulling fuses until the current drops off or the light goes out. That's fine, except this jeep does not have a fuse box (or any fuses at all). One symptom which may help anyone who knows the M38A1 is that my headlights will sometimes just turn off when I'm driving at night (!!!) and then turn back on again when I kick the high beam foot switch a few times (but sometimes not even then). So I'm thinking the short is likely related to this symptom. Anyways- any tips here for finding shorts in an old wiring system like this (and a 24V one at that)???

Thanks in advance, Steve

Reply to
steve.newhouse
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Just a thought,

If it drains a good / fully charged battery in 1-2 days, then there is a significant current draw, that could rise the temperature of the defective part. Check for warm relays or wiring or switches, to find the problem.

Regards, Bill Spiliotopoulos, '96 XJ, '06 TJ.

Reply to
Bill Spiliotopoulos

Dont know if this helps, but I had the same thing with lights in my 87 Ford F150, changed the floor button and never had a problem again.

Reply to
Greg

I have never had the pleasure of any Jeep that old but lots of practice on electrical systems of the era.

This is a generator based system, there are about 3 major items hooked up when the engine is off: the starter switch /starter solenoid, the light switch, and the voltage cutout relay in the voltage regulator. The

24 to 48 hour drain time would make me think you have a stuck relay in the voltage regulator. Disconnect the line from battery to regulator and see what happens.

Your headlight problem would > Hello,

Reply to
RoyJ

I will second that and add that there are some poorly built aftermarket switches out there so even going to a dealer might be better for the part.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail > Dont know if this helps, but I had the same thing with lights in my 87
Reply to
Mike Romain

Sounds like your light switch may be shorting to ground. You could try disconnecting that over night to see if the battery no longer gets drained.

Reply to
nrs

Thanks so much for the help guys, I will try your suggestions over the weekend and see what I can find out.

Reply to
steve.newhouse

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