Current draw killing battery(s)

[hatzie]

Originally Posted by '68OrangeSunshine

The other day, 7/02 , the Tahoe wouldn't start. Fluke across the terminals read 11.11 VDC.
It's possible the Fog Light switch was left on. The driver side one is smashed, and I think the passenger side bulb is burned out. Don't remember any yellow lights [except Turn Signals] on the front. If that Switch is ON -- will there still be a current draw?

I took the '71 GMC to my Dr's appointment. Later, I put the Jimmy none-to-nose with the 'Hoe, hooked up the jumper cables and let it run five minutes, before trying the '03 Ignition Switch. It started fine. I disengaged cables and let the Tahoe run at 1500 - 2000 RPM for 15 - 20 minutes with the daytime headlights off. I shut it down and started it again. It was good.

Wednesday night, it started OK again and I ran it 2.5 miles to the supermarket. I noticed the Cabin Lights stayed off. After I loaded my groceries up, it started again, but I cut off the automatic-On headlights and ran the motor for a few minutes to charge. Then I took off for home. No traffic, so I slipped onto the street without stopping. I had a Green light, so I hit the throttle for home...
Just then a bunch of bright and colored lights were flashing behind me, and I realized -- in my shadow -- my Headlights were off. I switched them on.
I got pulled over but the Cop gave me a verbal warning about driving w/o lights at night, after I explained my screwy electric gremlins.

Factory fog lamps on the 2nd gen GMT800 are controlled by the BCM. The fogs switch off with the ignition.