Battery Getting Drained

[Green97]

Have something draining the battery overnite. Just started couple days ago. No lights on. Charge battery starts and runs fine. But charger never show fully charged light but chargeing at 4 amps. Fully charged shows when disconnected.Changed to known good battery, samething. Had alternator tested(twice) it is alting fine. No aftermarket goodies. Have chased wires looking for shorts, nuttin honey!! Any ideas? Hate electrical!!!! All lights work as should.

97 Yukon 5.7 4x4

[Green97]

Found the problem. I had noticed while checking things ice on th A/C line near the comp., didn't think much about it. While swapping the battery(son had done earlier swaps) I heard the A/C clutch kicking in and out. This was with all power off. Unpluged A/C pump and all is good. Do I need a new pump or is it in the switching? Don't need A/C but 4-5 days a year hear anyway(Western Wa. I can see Canada out my front door).

Thanks

[RayGMC]

Recirculation uses the A/C pump, even with the Heater on. Dunno if it will harm anything without it though.

[Stevens03]

voltage regulator or just simply a bad battery. I had one that tested fine, charged fine, but would let me stranded about every 3-5 days. I replaced the battery and all was good in the world again.

[philzinn]

I have always wondered why my 2002 Sierra would get a clicking sound when I was just sitting waiting at idle. It must be the recirculation pump kicking on and off.