Aftermarket stereo problem
 

So i recently bought a 2000 Monte Carlo SS and I'm trying to put a new headunit in it. I have a Pioneer from my old car and got the factory adapter for the Monte, but when i connected all the wires the headunit wouldn't turn on. Someone told me that the stock stereo has part of the security system in it and that's what's causing problems. Does anyone know what to do/how to get around this? Help much appreciated.

What harness are you using? When I installed one using a gm09sr I had no problems getting the deck to power up. But I also did an install using a Y harness and when I attempted to turn the deck on, nothing. Turns out that harness didn't supply the switched turn on wire so I had to run one from the fuse block to get it to power up.

What you need to do is find out exactly what the problem is instead of guessing. So turn the car on and then turn the deck on, get a multimeter and check for voltage on the backside of the harness at the neg and power wires on it. If you get voltage, then that's not the problem, if you don't have voltage then you need to do what I did.

the security is in the stock deck, not the bcm as far as i know so it shouldn't matter, i'd say you wired up something backwards. check your wiring, the 3 wires you need to get the deck to turn on are red, black, and yellow, connect only those and see what happens, black is ground, yellow is a constant 12v and red is another 12v that turns on with the car, the one that turns on the deck if i remember.

Well, let's give him the benefit of the doubt that he wired the black wire to a black wire.....so that leaves the red and yellow wires.....even if he did wire them backwards the deck would still power up, it just wouldn't retain the settings.