2003 Grand Prix GT - Electrical Problems

Hi - It's only 1 year that I bought my 2003 Grand Prix Gt and I've had this problem with the electrical system(s): HVAC, trip computer, front passenger power window, and automatic headlights all work only intermittently. If the AC is left on max with fan on 5 (when the HVAC is not working), it might suddenly come on while driving. If you try to turn the fan down, however, the whole HVAC goes completely out again and nothing will get it back. The emergency brake release normally turns on the headlights, but only does so once in a while. The rest of the time I have to manually turn on the headlights. Interestingly, recently one of the headlights was out, so with the car on I started to remove the light for replacement. When i got the housing off, the light came on, so I put it back (without changing). Sure enough the light went out again & this morning I got a ticket for it. The trip computer is only on when the HVAC is on. The passenger power window rarely works, but works once in a while.
It seems to me that these problems are all related, but I can't find the problem to fix it. I'm going to check the cables for damage & obvious problems of that sort, but any help or suggestions would be greatly appreciated.

You have a bad ignition switch/harness assembly. It's a common issue on these cars and causes a lot of electrical gremlins, including all of those you mention. AC-Delco part #D1491D (GM# 26068757).

Here's a link to the replacement proceedure from our tips and maintenance section.

http://www.automotiveforums.com/vbulletin/showthread.php?t=653340

Agreed!

Thanks guys - I got the ignition switch and made the change, and all the major problems have gone away. The only thing, for anyone who may run into this problem in the future, the job required 2 sizes (not sure of sizes) of female torx bits to remove screws that had male torx heads. I don't think I ever saw this before - usually it's male bit into female screw, similar to 'Allen'. I was able to fenagle tem with needle-nose pliers, etc. Anyways, thanks for the great advice. I was able to find the part at a great price (~$84), with free next day delivery from OEHQ.com. Aftermarket parts were around $120, while OEHQ.com had the OEM part for almost $40 less! Thanks!!!!

Thanks for the feedback, glad to hear you got her fixed.