battery drains itself without use OVERNIGHT

[cowseats]

I have a 1999 Chevy Tahoe, and lately the battery has been draining itself.

Even after sitting in the driveway over night the battery although full the night before will need to be boosted the next morning.

My mechanic has looked at it for over a week now checking every so often to see mechanically what is going on, but has yet to come up with anything.


He doesnt think it is the alternator, because the battery just drains itself without use.


Anyone else ever had this problem?
Or does anyone have a clue what I should be looking for?
All help greatly appreciated.

Thanks


No dash lights, or radio , or doors left open that would cause any effect on battery use.
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[010175]

I have 1999 suburban and it did the same thing. One night I went out to look at it and I found the inside light on. The car was locked and nobody had open the door. I pulled the inside light fuse. Upon reviewing the book I found that the headlight switch has a dome override button. The button would not stay in and I replaced the headlight switch {off ebay for 32.00, easy to do the molding pops off around the dash} and I have not had the problem again, I also replaced the door light switch because when you open the door the inside light would not come on with out shaking the switch.

[pa-deer]

My '99 Tahoe has the same issue with interior lights coming on any time they please. I replaced the headlamp switch described in the previous reply, ok for a short time then they acted up again. Was told I needed to replace the control module under the dash that controls the locks, window switches, lights, etc. which I did ($200.00) and that worked for about 10 days. I looked at the switch for the rear hatch and the "O" ring was shot and I thought water might be getting into the switch and making the connection so I replaced that and let it sit inside for a day or two and then one afternoon the lights were on again. I would be interested if your headlamp switch replacement works, maybe I just got bad one? In any case over-riding the interior lamps works but you always have a dark car to enter and like anything else you pay for the lights they should work when you need them. Any other suggestions are appreciated.

[010175]

Yes - replacing the headlight switch worked for me. The push in button that I paper clip jammed in stopped the battery drain for a year befor I replaced the switch. A long test!! One of the other posts in the suburban or yukon said that they found that the sunvisor mirror was on even with the mirror door was close. Dave