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Aftermarket H/U Installation

53145 Views 55 Replies 27 Participants Last post by  TRAVIS71
Last week I put in an Alpine H/U. My particular model does not have an internal amp, so I used the stock amp by running the preouts to the speaker level outputs of the amp (essentiailly the stock speaker wires on the harness). This also allowed me to continue to use the stock sub. I attempted a lot of tiral and error and will add all that I have learned. Excuse how dirty my car is.

To get to the radio first remove the silver trim panel above the glove box.

Open the glove box.

Pull the panel off from the bottom.

Panel Looks like this. If it doesn't match put it back haha :p

Next pop the top edge of the trim piece below the steering wheel out and then remove the trim panel with the driver control center buttons. It is on the left of the radio trim piece and right of the steering wheel.

You will have to pull on the tab, shown in the picture below, to remove the center trim panel. It is the only real place to get fingers behind and pull. It is possible to pull some on the bottom, but I was never successful. The trim piece resists strongly, but didn't break. It may need to be worked awhile, but it will come off.

Here is how it looks once the trim and radio are removed. Four screws hold the radio in. The wiring harness adaptor ($5 from a local place I have connections) is plugged in for a test look. I removed all the excess wires I didn't need after this.

I removed the Stock Reciever relocation plug (used for recievers that have driver info built in). Can't think of anything else I removed, but don't remove the power antena/remote line of the harness. They are needed to turn on the factory amp (I made this mistake, but luckily kept the wire).

Here is the factory radio removed.

Now its time to play with the wires.

This is normally straightforward, but I'm going to go over it anyway.

Yellow on the adaptor harness goes to the constant power of the h/u harness
Black on the adpator goes to the groud of the h/u harness.
Blue is a power antenae lead or as used in the Pioneer system a turn on for the factory amp. This will attach to the remote line of the h/u harness. If you need to run any other amps connect their remote lead here as well. Use a twist cap, so remote lines can be added that do not run through the harness. It makes removal and install easier.
There is no turn on/ignition lead to turn the h/u on and off with the harness. These new radios use a fancy bus system to turn on. Another member here has mentioned the only way to utilize this with an aftermarket radio is to buy a harness costing over $100. I am bypassing this system for that reason and some would consider it "ghetto", but it works. To turn the radio on and off with the car run a wire from the ignition fuse in the fuse box to the ignition lead in the h/u harness. Use a twist cap here as well.

I tried searching for a switched wire on the inside of the car, but gave up after a half hour or so and hooked it to the fuse. I plan on going back and searching some more. This would give a cleaner install.
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Actually a pretty decent do it yourself "how to". Good job man, I was the one that mentioned that harness. Its only neccessary if it messes with your door chimes and/or dash lights. You havent noticed any of that have you? This is a decent how to and if enough members would like we could sticky it if ya want?!?!
Not neccessarily... the thread is fine the way it is...
06CobaltSSSedan said:
Did you do anything to make your steering wheel audio controls work? Ive wanted to put a new HU in my car but I dont know if I wanna give up the wheel controls, I use them a lot!
This can be done easily, with a ~$30 module but you have to have a radio with a remote that you can program it with...
Show Off said:
hey guys, thought id add to this. im putting in a HU and went to best buy for the adapter box to get rid of the stereo and keep the dic.... well best buy doesnt carry these for our models. there carry the older ones pre 2005 (least thats what the guy told me). he said they had wired the stereo in manualy on a cobalt and wired in the dic, chimes and stuff with out the box. but i didnt risk it, i had delt with the stock stereo wired in under my drivers seat in my truck, im not doing it again.
so anyway i then went to crutchfield and talked to chad online and then called him. they just made this box, its still new so its not on the site yet. its part number: 120993303 and it cost me 129.00 usd...

also if u ever need to replace the front door speakers get the 5 1/4 set
you will then have to cut off the speaker off from where the supports meet the outer ring, so infact thats all you have is just a ring left. then align your speaker, mark and drill the holes and attach new speaker to that ring. i used my dremmel for this whole preocess, the speaker is mostly plastic, so youll be fine. then mount it back in with sliding bottom in first and then put back in the top screw. i didnt have time to take pics... sorry
if you dont understand, pm me and i will try to explain better. i have a bad time with typing.
He was wrong, I work at Best Buy and we do have them! SOrry bout the douchebag... ours are $120.99.
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