I just repaired my ac system and another issue popped up. (AC repair thread here: https://chevroletforum.com/forum/tah...burban-101224/)

99 GMC Suburban K1500 5.7L

While I was running the motor and charging the ac system after awhile of me letting it idle making sure everything was ok the motor just died. Somehow it’s drawing from the battery so it killed the battery. I just tested the alternator at the parts store and it come back ok.

So what’s strange about this is that up till now there hasn’t been any indication of a problem. I’ve driven the burb for over an hour at a time and it’s never drawn down the battery.

Is it possible the alternator test was wrong? Maybe the alternator is able to charge the battery at cruising speed but not at prolonged idle (like my ac recharge)?

Any other thoughts?

 

That is my take, alternator

 

After I posted on a hunch I went to a better parts store and tested it again and it failed. It’s possible it was the original as it had the Delco stamp on the back. Guess when driving it had just enough charge to not drain the battery but idleing in the driveway for 30min it didn’t. Replaced with a new unit and got a new battery as well.