Pulled the radio and found the old delco has 2 connectors, one 24 pin with 12 wires and a second plug with a black wire and a green and black stripe wire, are these for the factory amp and can I tie them into the harness? The new radio works fine but the amp isn't working with it

 

Don't cut any of the wires and save the original radio if you have a 6th Gen Monte Carlo that is how all the information is reset on that car.

 

Haven't cut any wires trying the schosche gm interface but it's got a 24 pin 12 wire connector, trying to find out about the other connector and can it be tied in if that's the factory amp in the trunk

 

So here is how those plugs on the back of the radio work.
- Small Plug - These are wires for XM and/or OnStar (depending on what your car is equipped with).
- The big plug is everything else.
- If your car has a factory amp, it can be found in the trunk, between the two 6x9 speakers.
- How the wiring works, the factory radio sends the left/right/front/back raw audio to the amp. I believe it also sends an amp turn on signal as well.
- The factory amp has two connectors.
- If I recall, the smaller of the two are the speaker inputs from the radio.
- The larger one is power, ground, speaker outputs.

I hope this helps a little bit.

 

The Monte doesn't have Onstar or XM so the plug in must be extra for upgrades then, therefore I can just ignore it, thanks for the input

 

In messing with GM engineering, since some of the wiring involves multiple harnesses, it is possible the harness used to provide that little plug is simply installed in all Montes of a certain year (regardless if they have OnStar or XM). Then when the wiring is to pass to yet another harness, that one might lack the wiring to continue the circuit.

But, anycase, yes, you can ignore that little guy