anyone know the wiring diagram for a grand am?

Question

i have a 2004 pontiac grand am, and am installing a new stereo. the old stereo has 18 pins, and i don't know what all the wires are for. i've tried looking online, but have only found models w/ 16 or 12 pins. does anyone know where to find it?

Answer 1

It's a little trickier than just a harness in this vehicle. The factory radio is tied into the vehicle data bus, and it generates all audible warning chimes in your car. That means if you remove the factory radio you'll lose your door chime, light-left-on chimes, and any other warning chimes. Also, the vehicle data bus system controls the on/off function of the radio, so there's no "accessory" power wire in the harness that an aftermarket radio needs.

The easiest and best way to install a new head unit in that car is an adapter module like this one:

http://www.crutchfield.com/S-9SRMAH0ozAC/cgi-bin/ProdView.asp?g=751&I=120GMRC02&search=data+bus

If you don't mind losing the warning chimes, you can purchase a standard harness like this one:

http://www.crutchfield.com/S-9SRMAH0ozAC/cgi-bin/ProdView.asp?search=70%2D2003&pm=9&i=120702003

You cannot use the red wire in this harness; you'll need to find an alternate source for your accessory power connection. I often use the heavy brown wire from the key switch; it's easy to get to with the factory radio removed.

Answer 2

use the expensive plug if not you will lose the
door chime
key in the ignition chime
airbag warning
gas cluster low fuel
and sometimes the milles and rpm stop and turn back on

Answer 3

Try the library they have most of them .
Good luck.