Recently I bought a Monte Carlo LS from my wife's Grandma, it was her Grandpa's car. He never drove it, like ever...25k miles. Anyway, it had a cassette deck in it and I dont think ive even touched a cassette in 20 years LOL. So I installed an aftermarket stereo and speakers, everything was fine, i bought the overpriced wiring harness hooked it all up, no problems, had the door chimes, car started and ran fine. the radio even stayed on till i opened the door (wasn't expecting that). I found an old amp and sub i had in my basement and figured I'd throw that in.....now that i did that i have no chimes when i get in the car and put the key in, and the car wont start. headlights come on, radio works if i turn it on manually dash lights come on everything has power. The display says low fuel (its full minus a few miles), service soon, security, battery in a loop. I'm assuming it has something to do with me disconnecting the battery to attach the amp power wire? I hope I gave enough info.



p.s. The wife is not happy

 

Disconnect the amp and sub,and see if the car starts.

Sounds like too much of a power draw.