VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt Generator Short?

I went out yesterday morning to start the truck ('53 3100 1/2 ton truck) and the battery (new 6 volt AGM) was dead (VOM showed 0.75 volts). With all wires disconnected from my 6-volt Delco generator I get the following readings:

From Field terminal to ground 0.2 ohm
From Armature terminal to ground 1.5 ohm

It looks to me like I have a short inside the generator. Am I right on this? Have I fried my expensive new battery? Any help greatly appreciated.

I would remove the voltage regulator cover and check to see if the cut-out contacts are "open". The cut-out relay is on the side of the regulator that has the two regulator mounting screws. When the generator is not charging (engine running or not) these contacts must be open. If closed with the engine off the generator will drain the battery.
The battery shoud be OK . I would start by gining it a slow charge.

Thanks for the info, I've got the battery on a very slow charge now and will get the generator and regulator tested Monday (there is an old-time rebuild shop near here).

Here are a few steps you can take.

Here are some steps to take.
1. Check battery water and general battery condition to
see if it will take and hold a charge....Load testing
may be necessary.
2. Check wiring for damage and make sure all
connections at generator, regulator and battery are
tight and free of corrosion.
3. Make sure fan belt is tight enough to drive
generator at full capacity.
4. Run engine at medium speed. Using a wire, touch one
end to regulator base and other end to a good ground.
If this corrects trouble, regulator is not properly
grounded anymore.
5. If test 4 does not correct trouble, make this test.
Connect a wire from regulator terminal marked "ARM" or
"GEN" to regulator terminal marked "BAT" with engine
running at medium speed. If charging rate increases,
replace old regulator.
6. If test 5 does not correct trouble, make this test.
Connect a wire from "FLD" Terminal of regulator to a
good ground with engine running at medium speed. If
Charging rate increases, replace old regulator.

If none of the above test show a bad regulator then
there is probably a problem in the generator itself.

Ken

hey Ken ...welcome to the chat!...Being one that needs help in the electrics area , I appreciate the list of tests you gave ....will save and use later !I have trouble finding this stuff in the search area of the forum ...