1999 Other GMC Models V8 Four Wheel Drive Automatic 85,000 miles
I bought this 1999 GMC Suburban new. It has been very good to me for 8 years now. However, recently, I've been hit with this interior light problem that drains her battery. I also have a 3rd party anti-theft alarm installed by the dealer when I bought it. From what I can tell, the alarm works off the interior lights, if lights go on without disarming, the alarm goes on. The problem is that the interior lights have developed a mind of their own. They come on and off randomly, no set pattern. Doesn't matter if the vehicle is on or off. I left the truck parked for several days while I was away and apparently the lights came on and the alarm went on until the battery drained. I recharge it and it held okay. Then I disarmed the alarm and same thing happened, a drained battery a few days later. I found that if I use the Dome Light Cutoff switch and keep the interior lights off, then it's okay. Only problem is that I can't use the interior lights or the alarm. I don't care about the alarm, but I would like my interior lights to work properly. I'm assume that GMC knows about this but ain't talking, why else would there be a dome light cutoff switch in the vehicle? I've never seen one before and my Silverado doesn't have one (well it does, but it has multiple purposes like keeping the headlights and fog lights off in the daytime). I was told that it could be a LCM, Light Control Module. But the dealer said that this truck, with keyless entry, does have one. Beyond that, the dealer wasn't much help. The sign that this guy was a dope was that he argued with my that GMC didn't make a Suburban in 1999 until I pointed it out to him in his parts manual - either that or I've been driving a phantom vehicle for the past 8 years. Anyway, any suggestions that doesn't drive (no pun) me to the poor house?