Trying to bypass UQ7 Bose amp in 04 Tahoe (already searched)

[Nick5811]

[edit: It does not appear to be possible to simply bypass the amplifier in this vehicle. It appears the signal comes in two channels, and leaves four channels, and trying to directly wire the signal did not work for me. My final work around was to run four sets of speaker wires from the head unit down into the center console, and connect them to the larger connector (C1) on the wiring harness with a Metra 70-2002 harness from Amazon for $4. I hope this helps someone else save a bunch of time and frustration.]

Hey guys, been a while I know. I tried the searching here and all over google; not working as well as it used to.

This will become a 'how to' when it's finally resolved. I feel like I'm close, I just have to sit down with the harness and the diagrams for a little while.

Anyways, here's my sitch:

I have an 04 Tahoe with the non-lux Bose package (UQ7 RPO, no Y91) with rear seat audio (RSA) but not DVD/Rear Seat Entertainment.

I bought a 2002 Avalanche that had a factory amplifier in it. I read on another forum how to bypass the amplifier using a metra harness (70-2002) that was reconfigured to basically loop the audio back into itself. About 15 minutes with my leatherman and this worked out great.

I'm trying to do this exact same thing on the Tahoe but I can't find any correct resources showing how it is done. Most of what I've found on the net has been upgrading from UQ7 to Y91 bose or people saying 'just yank out the crappy bose audio'. Both of these things are worthless to me.

What I've done so far:

I ripped the bose system out about a week after getting it in 2008 and threw all that s*** away. I ran new wires to some components in the front doors and put two amps under the console. Now I'm trying to sell the truck and I want to keep all my amps and speakers.

I pulled the amps and speakers (and wires for simplicity sake), and I replaced the speakers with new ones and hooked them up to factory wiring.

I'm leaving the pioneer dvd deck in the dash, so I wired it all up with the cheap metra harness (not the one for on star/door chimes) and wired the speaker leads together. I have power, but no sound to any of the speakers. This doesn't surprise me, since I ripped out the bose amplifier.

The big thick wiring harness under the console is spliced all back together as if it were stock. I have the RSA plug stuck into the RSA box in the back of the console. This leaves me with another 24 pin radio type connector (probably from the bose amp), a smaller plug with about 8 wires that I think belong to on star, and a big monstrous black plug with a locking lever on it.

My plan to fix this:

I'm about to go buy another 70-2002 harness and use the wiring diagrams I got off of Autozone.com and see if I can wire together a bypass for the amp like I did on the avalanche using the 24 pin connector in the console harness. I believe this will give me all four speakers running off the deck without on star.


I need your help:

Does anyone have a pin-out diagram for the non-lux Bose amp from this year/series (the sound goes in the amp from the radio, and then comes out the amp into different wires that feed the speakers)?

Does anyone know what the big black connector with the locking lever might go to?
[edit: a moment of enlightenment occurred when I unplugged the big thick harness from the rear cigarette lighter and found this entire harness isn't plugged into the truck anywhere...Ah Ha! That's where the big fat connector goes!]

[damion]

You could always rewire the factory harness if you have time. Basically take the wires from the pioneer and figure out which wires woulda came out of the factory amp.

[Nick5811]

Okay, so I found wiring diagrams for pretty much every part of every car on Autozone.com for free, you just have to give them an email address to spam. I'm fishing through it, and I see a diagram listing output wiring and colors from the amp to each of the speakers.

After hours of looking on the web, pulling the harness out of the car, pouring over diagrams and then finally figuring out all the wires on the plugs I find this. I guess it helps to have the right terms when searching (UQ7 C1 C2) geez.

http://ww2.justanswer.com/uploads/Bluegorilla/2010-12-08_010642_2006_amp_wiring.pdf

So now I've decoded the wiring and the plugs that go into the stock amp:

C2 (the small plug) has two inputs; Left and Right (plus and minus).
C1 (the big plug) has left/right/front/rear (plus/minus), mute, amp power (remote), four outs for the factory sub, etc.

C2 is the "input" plug and C1 is "output" plug.(?)

I guess this makes sense if the factory stereo just sent two channels of info to the amp (left and right), and the amp did all the sound processing and broke it down into front and rear.

So from C2 I need to run one wire to each of the four middle terminals (B, C, F, G).

B-->left side positive speakers-->A5,A9
C--> right side positive speakers-->A7,A11
G--> left side negative speakers-->A6,A10
F-->right side negative speakers-->A8,A12

Then, in theory, if I do this and plug it all in, I should have equal sound out of all four speakers. I won't have the ability to fade my sound front to rear, but I should get music from the speakers.

Right?

[Nick5811]

Okay, so I tried out my theory, and it did not work. At all.

What did work was running speaker wire from the back of the deck to C1's speaker terminals (A5-A12). Apparently the connector behind the stereo is only good for illumination and something else; everything else is ran from the fuse box. Oh well. Nice waste of a bunch of time but it was fun re-living the days of messing around with this stupid crap.

Moral of the story: you can't bypass the amp in the Tahoe like you can in the Avy. Do it the easy/hack job way and run new wires from the deck to the C1 connector. 4 wires, about 4-5 feet in length and plug them into a 70-2002 or equivalent metra adapter. You can be done in 20 minutes if you've already got the dash and console apart.