93 grand am stalling

hello all, i am new here, and i am in desperate need of some help. i have a 93 grand am se, 6cyl. 3100 motor. here is the issue, the car starts up, the motor races for a minute or so, and runs normal. i apply the break, the car stalls. i turn on the rear defogger, the car stalls. whats going on in my insturment panel?? well.... before i start the car, all gauges are normal. as soon as i start the car, my gas gauge pins to full. oh... the little red light on the rear defogger button, stays on, gets brighter when i apply the breaks. does anyone have any idea as to what the hell is going on with the car?? if so, please, please help me. thank you in advanced.

It's a long shot, but I would first check for a bad ground wire. Start by checking the ground wire between the battery and the chassis, and the battery and the engine block. If all is good, check the ground splice packs for the ECM. It seems like the ECM is pulling ground from another source other than it's intended ground. And since the brake switch and defroster switch both sit at ground until they are active, this would make sense (once they become active the read 12v instead of ground). I just had a brain storm. The brake switch, defrost switch and fuel pump all have one thing in common: they all have wires that run to the back of the car in a conduit. Has any work been done to the car at all, be it mechanical, or a stereo or alarm been installed recently?


Marc

there was a stereo put in, but it is useing the factory harness, and an adapter to fit the factory harness. that was one of the things i thought of when it started to happen. so... i took the stereo out, and it still proceeded to stall when i hit the brakes, or turned on the rear defroster. i'll check the ground for the ECM, if you can give me a clue as to where the heck the ECM is. i am some what car smart, but... with all this technology on them, its a little hard to keep up with everything. my main car, 86 buick regal, has an olds 350 rocket under the hood, and none of this computer stuff attached to it, pure, unadulterated power!