So I bought my Head Unit, Pioneer DEH-P4200ub.

Bought all the installation gear I needed. I connected the wires correctly and when I plug everything in the unit turns on but the speakers aren't working. With the factory radio they work fine.

I called best buy and the dude said that because I have onstar I need a special harness that's 100 bucks, and if I don't use it that the door chime won't work and the check engine light will come on.

So my question is do I really need this special harness to make the speakers work as well? Is there any way I can bypass this? Or am I just not hooking it up right?

Not sure if all vehicles with OnStar HAVE to have that special harness but as far as I know you should be able to find a harness or splice and wire the factory harness that should keep you from having to buy the expensive one. However you will most probably lose your OnStar...

edit: A buddy of mine had the same problem so he had to use like a Saturn harness or something to bypass the OnStar. Just needed to run an ignition wire.

Edited December 31, 201014 yr by xAndrewx

Is there a blue wire on the harness that plugs into the factory wiring?

There's a blue wire on the harness I bought yes. It says power but it doesn't plug in right to the factory harness.

Edit: I could really care less if I had the onstar. If anybody knows the wires I need to cut and splice who's had experience with this problem your help would be much appreciated. If not I'll just buy the expensive harness..

Edited December 31, 201014 yr by rodney

There's a blue wire on the harness I bought yes. It says power but it doesn't plug in right to the factory harness.

Edit: I could really care less if I had the onstar. If anybody knows the wires I need to cut and splice who's had experience with this problem your help would be much appreciated. If not I'll just buy the expensive harness..

Just splice the factory harness?

There's a blue wire on the harness I bought yes. It says power but it doesn't plug in right to the factory harness.

Edit: I could really care less if I had the onstar. If anybody knows the wires I need to cut and splice who's had experience with this problem your help would be much appreciated. If not I'll just buy the expensive harness..

Just splice the factory harness?

No horrible idea, never do this. EVER.

What brand wiring kit do you have?

Do you have the Bose system?

There's a blue wire on the harness I bought yes. It says power but it doesn't plug in right to the factory harness.

Edit: I could really care less if I had the onstar. If anybody knows the wires I need to cut and splice who's had experience with this problem your help would be much appreciated. If not I'll just buy the expensive harness..

Just splice the factory harness?

No horrible idea, never do this. EVER.

What brand wiring kit do you have?

lol, I'm just saying it could work. I don't prefer it.

Don't EVER EVER EVER EVER EVER hack a harness off. For 2 reasons. You will not figure anything out unless you know exactly what you're looking for and probably have to pay someone to go ion and fix stuff, and usually when people hack harnesses off, they cut everything at the same time. When you cut power and grounds at the same time with a METAL cutters, you short out the power circuits and blow fuses.

Anyways, you shouldn't need anything special if you don't care about on star. Just sounds like the factory amp is not powering up. Find the blue or blue with white wire on the aftermarket harness and tie it into any switched power source whether it is the remote turn on off the aftermarket radio or the acc power provided to the radio. It will work either way.

Don't EVER EVER EVER EVER EVER hack a harness off. For 2 reasons. You will not figure anything out unless you know exactly what you're looking for and probably have to pay someone to go ion and fix stuff, and usually when people hack harnesses off, they cut everything at the same time. When you cut power and grounds at the same time with a METAL cutters, you short out the power circuits and blow fuses.

Anyways, you shouldn't need anything special if you don't care about on star. Just sounds like the factory amp is not powering up. Find the blue or blue with white wire on the aftermarket harness and tie it into any switched power source whether it is the remote turn on off the aftermarket radio or the acc power provided to the radio. It will work either way.

Right here.

I connected the blue wire from the aftermarket harness to the blue and white wire from the pioneer harness and still no sound. I double checked all the wires to see if I did it right and I did. The head unit powers up and everything but the speakers don't work. I want to just go ahead and buy the special harness but I can't find the exact one I need.

My 02 tahoe has onstar but not Bose.

It isn't the fault of the harness, the only thing the "special" one gives you are the stupid through the radio sounds. No interest in that if you ask me and I sure the hell didn't pay for it in my 02.

So should I just get a different harness. Like a metra one? The one I have now is scoshe or something. From wal mart.. I was hoping you'd reply to this M5.

I'll take some pictures when I get home. I'm at work right now.

buy one and compare pin outs. Provided they are the same pin outs and both are as complete as one another, you could take one back. If they do match up, maybe try to jump the turn on lead to a 12 volt source. It's unlikely but I have seen harnesses where the pins don't make contact with the factory harness.

Have you tested for power in all the appropriate places with a meter?

So should I just get a different harness. Like a metra one? The one I have now is scoshe or something. From wal mart.. I was hoping you'd reply to this M5.

I'll take some pictures when I get home. I'm at work right now.

This is the whole issue.

Stop trying to do stuff the cheap way, do it right the first time.

So should I just get a different harness. Like a metra one? The one I have now is scoshe or something. From wal mart.. I was hoping you'd reply to this M5.

I'll take some pictures when I get home. I'm at work right now.

This is the whole issue.

Stop trying to do stuff the cheap way, do it right the first time.

i bended the pins on one of the scosche ones lol.

You could run new wires to all the speakers from the back of the deck.

That what I was thinking too engar.

Well I gues the reason I bought it from wal Mart was because that's where I bought the deck from. So it just seemed convenient.

Nothing wrong with a walmart harness...unless you are unlucky and got a defective one. Have you checked all the leads and connections as requested? I surely wouldn't buy another until I did. If you were here I have a couple that I won't be using, but hardly worth mailing.

Do you have a factory amp in your tahoe?