I had a fun filled day today. I installed my new stereo system in mk 04 Sunfire. I need help there is no acessory circuit in the car due to the wonderful BCM! Please tell me he so can tap into a accessory circuit so I can play the radio in the accessory position. I have searched the forum and they talk about using the brown wiper wire circuit or the orange ignition wire circuit. There are a lot of wires under there any help would be very helpful.

I like cheese in my mash potatoes

http://members.shaw.ca/johnz24/howto/7/7.html

^^ From the sticky

Quote:

The switched +12V wire

In order to turn your new aftermarket deck on and off with the ignition, you have to tap onto a wire that carries +12V when the car is ON and in ACC. There's a brown wire in the ignition harness that you can tap. It's a heavy wire (12 gauge) compared to most other wires around it. There arealso two red wires, and a yellow, pink and orange there too - if GM changes the wire colours, use a voltmeter to check which wire carries +12V during the ACC and ON key positions. If you are tapping this wire - FUSE IT!

An 'easy' alternative is to use a fuse tap on the windshield wiper fuse. This is a plug which replaces the factory fuse and adds a new fuse (along with the original one) and has a wire for the new circuit. Using the windshield wiper fuse is an old installer trick, and it sure does work! Plus by using the fuse tap, you don't have to cut any of the factory wiring. You also don't need to worry about overloading any existing circuits, because ineffect you are creating a new one.

Thanks to all I found the brown wire and tapped into it and all is well.

Mine was the same way....why is there no accessory wire in the harness????

EVOFire (DesertTuners) wrote:Mine was the same way....why is there no accessory wire in the harness????

good question...lol

The radio has constant power, and the Class 2 bus is used by the Body Control Module to turn things on and off. The radio is the big one... but also the fog lights.. some other stuff..

so when installing an aftermarket stereo, how do we correct this? the harness in my car was all f'ed up when i bought it. so would would replacing the harness with a new one work. seriously EVERY wire in the harness was cut and spliced...