Battery going dead...What else is there?

[chrisq]

Hi All,
I have a 1990 EZ GO marathon & my battery is not charging. I have tried 2 different starter/generators & 3 different voltage regulators to no avail. I have taken the green wire off the S/G and grounded it. I get 15+ volts if i do that. Otherwise i get 12.9V. What else do I need to check?

[cart around]

The green wire stays on the starter end. It gets removed from the voltage regulator, and gets grounded to test.

Tell us what happens then

Make sure the battery has the ability to take a charge.

If you happened to do the test the way I described, and the voltage climbed to 15+ volts, that is a bad voltage regulator.

[chrisq]

Yes, this is the procedure I have been doing to test. Green wire stays on starter end. Just checked it again after charging battery. Battery checks 13V with engine off. 13.5V with engine running. 17V with green wire grounded.
I too have been under the impression that the VR was faulty. I have ordered 3 new voltage regulators from 3 different retailers & I get the same result with each of them. That got me to thinking that maybe I'm missing something. What are the odds of getting 3 bad voltage regulators?

[rvkersh]

13.5 - 14.5 would be a good voltage output from the charging system. 13 volt volts at the battery could be just a surface charge, load test the battery then re-check it's voltage. Could be a bad battery or ground.

[chrisq]

I agree. I think this is a surface charge. I checked it right after an overnight charge. I normally get about 12V at battery & 12.5V to 12.9V when charging. Ground seems to be good, if I am checking it correctly...I put one end of ohmmeter on battery & the other on frame & get 0.00 resistance. Also, battery is new...

[chrisq]

UPDATE>>> Well, I'm still not sure if all 3 brand new voltage regulators from 3 different companies were bad or not, but I do know that they would NOT work on my cart. I ended up taking the case off of the old & new regulators & comparing them. My old one had an screw where the voltage coming out of the regulator could be ADJUSTED up or down. All of the new ones didnt have any adjustment. I noticed that a wire was burned out on my old one. Had a new wire soldered in & Bingo! a fully working charging system....