gmwillys, Do you think he has a 24 volt regulator in a converted 12 volt Jeep? Was there a 12 volt M38A1? How did they get the 24 volts?
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gmwillys, Do you think he has a 24 volt regulator in a converted 12 volt Jeep? Was there a 12 volt M38A1? How did they get the 24 volts?
One thing we've learned is to never say "Never".
But, the M38A1 was a 24-volt vehicle. It used two 12-volt batteries in series to get the 24-volts. The creature we are getting a description of is kind of a giraffelephant. We have a 6-volt starter, a 12-volt battery and a generator that is charging a 12-volt battery at 17-volts.
IF - and IF - he has a 24-volt generator driving a 12-volt regulator, it could charge that high. OR - if he still has a 24-volt system with just ONE 12-volt battery, that would explain the 17-volt charge voltage.
I would like to see pictures of:
A. The Generator. The original M38A1 generator can't be mistaken for anything else with the double pulleys and the cable set it used.
B. The voltage regulator: Again, nothing else looks like an M38A1 regulator with the two aircraft-like quick disconnect connectors on the unit.
But, as we have learned - when Bubba, Junior and Leroy go through the parts bin and whip up a contraption, it's really hard to reverse engineer it...
Please, some pictures of the generator and regulator.
Attachment 5334 Attachment 5335
The generator has "12-volt" stamped into the case (I know that means nothing) and from some research, everything says it's a 12-volt. The voltage regulator appears fairly new and I don't see an adjustment on it.
I believe in the 12 volt markings as being true. You can pull the cover off of the regulator and adjust the voltage output by adjusting the contacts. The following pdf explains the procedure;
http://www.ruiter.ca/mc/info/PDFs/1R-116.pdf
There was not a 12 volt M38A1 from new. With the expense of the 24 volt replacement parts and the fear of the unknown, many of these parts were swapped with 12 volt equipment. Me personally, I like the 24 set ups. The parts are heavy duty, and generally work without issue unless a harness has been spliced or dry rotted. The same can be said for 6 volt systems. I like my 2A because it has retained it's 6 volt system. The components are heavier, and produces more torque for starting, but can withstand having 12 volt applied for short amounts of time if you needed to jump it off....Just don't turn on any lights, because you'll be buying bulbs.
I think we're starting to see what's been done to the vehicle, a major 12-volt conversion that may or may not have been done well.
The voltage regulator is a commercial (vs. MIL-SPEC) regulator. The VBT photo is the original M38A1 regulator - obviously not what you have! We'll assume the generator is a 12-volt generator. The wires connecting to the regulator are a modified wiring harness that looks a lot like a factory harness (see the attached photo) with wires about the right color.
As a first step, I would replace the voltage regulator. You can adjust the voltage regulator relay a bit, (you have to open it up and bend a tab on a spring) but if it's putting out 17 volts, it's beyond adjusting. I suspect a stuck voltage regulator relay (points burned and welded together).
Here is one of the universal three-terminal (Field/Armature/Battery) regulators that fit most any of the two terminal generators:
https://www.autozone.com/starting-ch...tor/319661_0_0
Meter things out to be sure someone hasn't switched a wire somewhere.
How about a picture of the passenger side of the engine bay so we can see the wiring and how it may have been modified?
We'll figure this out.
(Oh by the way, a properly operating 12-volt system will work just fine...).
I installed the voltage regulator LarrBeard and after starting it, the new voltage regulator began smoking. The Arm wire melted and I probably fried the voltage regulator too. I did notice this regulator is 6-volt. Could that be the issue? Thanks.
I suspect that a 6-volt regulator on a 12-volt generator is going to be fried, especially if it has actually smoked. My suspicion is that the coil on the voltage regulator relay drew way too much current and burned out. Even if that relay opened and put the control resistance in series with the field, the 6-volt resistance could not limit the field current in the 12-volt generator and after that, it was a contest as to what was going to smoke next.
You have a generator that probably hasn't been damaged - they're tough critters - and your battery has been compromised by the 17-volt high current charge condition. In the short term, I'd try a 12-volt regulator and a new armature wire. If that settles things down, you probably should think about a new battery.
Again, make sure the wires are hooked up to the right places.
(I'm not going to make any smart aleck comments about letting out the magic smoke ... )