Dreaded Tahoe with 6 speaker system

I just replaced my HU in my 99 chevy tahoe.   Rear door speakers fail to work. 

*Information*

• It is not a bose system.
• The factory amp is under the steering column.
• I didn't use a wiring harness.
• I have everything working but those 2 rear door speakers.
• I DO have the pink wire in the harness connected to the remote ant on the HU.  I can hear the relay click on the amp when I connect the wire.

My left-over wires out of the harness include a PURPLE / white,  DarkGREEN/ black,  Darkgreen, and a grey.

After thoroughly looking threw these forums for a wiring diagram of the factory amp, I am coming up short.  I would love to keep it there until I put in a mid/highs amp.    Without a wiring diagram, I am coming up short.   Can anyone help me troubleshoot this?  Of coarse I can rip the factory amp out and run new wires to the HU, but I would rather not have all 4 rear speakers on my HU without an amp.  I live in Tx, it is hot enough here

Thanks in advance,

Cypsteel

Thanks for your reply Raven.

Left Rear Ceiling:

• Brown+
• Yellow-

Right Rear Ceiling:

• Dark Blue+
• Light Blue-

These ceiling speakers are both working and I am sure of these because I have hooked them up seperately also.   I just cant seem to find the input wires for the factory amp that runs the rear door speakers.   As I mentioned before, I can hear the relay click on when I touch the pink wire.   If I can figure out where the amp gets its input from, I can hopefuly troubleshoot it further.

Anyone knwo what fuse the factory amp uses?

After looking at the wireharness in the light   the left over wires are:

• Grey:
• PURPLE / White:
• Dark Green:
• GREEN / WHITE:

I think grey is the dimmer...and I have checked the other combinations with no results.