Starting and charging problems with battery drain

[kzman77]

I tried to jump my excursion yesterday and finally got it started. It ran fine and then I shut it off for the evening. I immediately metered the battery as it was resting and the voltage was 11.95. This morning I went out and metered it and it said 4 volts! Now I know no interior or exterior lights were left on as I double checked last night after shutting everything off. Is there a way to test and see if there is a short circuit? I was thinking of switching the Multimeter to amps to see if there was current draw and then individually removing fuses until the problem subsides. Anyone have any ideas? I really don't have the money right now to take it to a shop so this is something I need to fix on my own. Thanks agai.

[Stroken7.3]

Have the alternator checked, maybe the voltage regulator is stuck open.

[kzman77]

Thats a good call but I already did that two days ago and autozone claims it passed their test with flying colors. I did meter the output voltage a few times and it was all over the place at idle; ranging from 12.6volts to 13.5 volts and it peaked at 13.9 volts when I had my lady rev the engine to 2000rpm.

[cj45lc]

The batts should be closer to 12.5 when you first shut it off, the alt should be close to 14.5. If it was me I'd unhook the alt overnight & check batts in the am. Sounds like alt to me

[Stroken7.3]

Your alternator will still charge fine, but if the regulator is stuck open it will let the batteries drain. I went through the same thing with mine and thats what it ended up being. Bought a new alternator and all is good. Hope you get it fixed soon.

[Stroken7.3]

Originally Posted by cj45lc

The batts should be closer to 12.5 when you first shut it off, the alt should be close to 14.5. If it was me I'd unhook the alt overnight & check batts in the am. Sounds like alt to me

I should have paid more attention to this. If your not above 14.0 volts your alternator is junk. These trucks are pickey from what I've noticed about voltage output.

[kzman77]

Thanks for all of your help guys

[Stroken7.3]

No problem. Welcome to the ORG

[kzman77]

What's a good brand of alternator to use to replace the existing one?

[Stroken7.3]

Not AutoZone.