| Battery drain caused by faulty Dimmer switch---->
I recently had a few episodes where I had to boost the Battery (mornings) because of low or no crank voltage. I took the car (03 CTS) to the Dealer yesterday for service and heard back from them in the afternoon. It was explained to me that the Dimmer switch located on the upper console was defective. That the problem "has no fix". The only option that prevents this issue is to make sure that the dimmer switch is set at mid-level and not to close to the detent (most brightest setting) on the switch.
Apparently, this is a common problem with 03-04 CTSs.
Somehow, if the switch is set to and left on the brightest illumination panel setting, it causes an override on the electrical system that keeps draining the battery even while the car is turned off.
I was given a computer printout of the explanation along with a diagram of the position the Switch should be set to. I'll try to post these instructions next week. (.... Off to Vegas in the morning).
I am amazed that GM has not developed a cure for this problem.???
Thought I'd share this info just in case y'all are having acute Battery drain issues.
Drive Safely. | 
