Cadillac Repair: Dead Battery....Illuminated entry system, cadillac eldorado, interior lamps

Question
I have a 1999 Cadillac Eldorado cts.  On four different occasions in the past three weeks I found it had dead battery on first start of the day.  At first I thought a door was left ajar, but the last time it was dead the interior lights were barely glowing. I had checked the night before and they were out and had to have come on during the night. I think the problem is with the controller for the lamps. Can you tell me where the controller for the interior lamps are located so I can replace it. I will pull the fuse for the interior lights until I get this fixed.  Finally, why didn't the inadvertent kill the power? Where is the control or fuse located for it? Any other information you can supply will e appreciated. Thank you, Cliff Croft

Answer
Cliff,
First of all, I'm curious about the model of your car. You say it's a '99 Eldorado "cts"? I'm assuming you mean "ETC".
Anyway, there is no "lamp controller" that controls all interior lamps on your car. The PZM (body control module) controls a couple but other than that, the rest are simply controlled by switches etc.
Your car should not go dead if everything is working properly. I'd start by checking the battery and connections, and then have the lights that you say are staying one verified to see if they are a couple that are PZM controlled or not. If so, troubleshoot the PZM, if not troubleshoot the switches that control the lamps in question.