I just installed my aftermarket head unit last night. Things went well, but there was a mysterious *third* wire harness that was plugged into the stock head unit. (non-Bose). My harness kit from Crutchfield only had two of them. When I installed the aftermarket head unit, I ended up leaving that mysterious third harness unused.

Any ideas what the third harness does? Since I swapped head units, I have virtually no AM reception. Could it have something to do with that?

 

Doubt the third harness had anything to do with your am reception. Ususally its part of the vehicle security.

 

It might be a connection from the navigation unit to play the nav audio through the stereo (if you have the nav).

If you didn't hook up the power antenna wire, the antenna amplifier will not function. This could explain your reception.

 

Power antenna? As in amplified antenna? Ah heck. I hate those. If that's the case, then I suppose I'll have to buy an antenna amplifier module. Had to do the same for my install in my Audi, as it also had an amped antenna.

 

Do you have a 2004 model? I noticed the extra harness as well. I ended up not using it. This harness was not there in the DIY writeup photos.

 

i have an 04 also and had no harnesses left over (enthusiast model)

 

It's an amplified antenna. All you have to do is connect the power antenna terminal in the factory headunit plug to either a power antenna or amp remote lead on your headunit. That's what I did, and it's fine.

 

I only had two harness.

 

Gotcha. But which wire coming out of the factory harness leads to the antenna amp?

 

If your headunit install used a snap-on plug like the metra plug so as not to cut the factory harness, it's labelled on the wire and on the packaging that the plug came with. It should be blue, maybe blue with a white stripe.

 

Ahh... is *that* what that wire was? Labelled "power antenna". Doh! I figured it was just another remote signal lead intended for a motorized antenna. (For powering on remote devices, etc.) Since the Z doesn't have that, I just left it unplugged. Heck, now I have to go pull that dash off again and hook it up.

 

Doh! I just noticed the misspelling I did on the subject of this thread, and it's far too late to edit it.

As a follow-up, I just hooked up that power antenna wire mentioned above, and my radio reception has improved dramatically.

 

I just replaced my HU with a Pionerr DEH-P850MP and I had 4 plugs in the back of my Bose stereo. I only used 2 though in my new install.

 

Yup, my non-Bose system had 3 harnesses but I only used 2. Does the Bose system come with a cd changer? That might be your 4th harness. I have no idea what that 3rd harness in my car is. Nothing seems to be affected, though.

 

yes it does have a cd changer buit into it. 1 of the 4 plugs only had 1 wire coming out of it. Who knows why. I didnt hook anything to 2 of the plugs and nothing has melted yet. Everything functions as it should.

 

I don't think anything will melt by leaving harnesses unplugged. The only problem would be loss of functionality.

 

i know it, i was being sarcastic

 

If it's an 04 model, the third harness is for the optional satellite radio receiver. The other end is in the rear of the vehicle, and the optional Sirius receiver plugs in at that spot.

Hope this helps...