2009 Honda Accord EXL - No nav system; premium sound system (I think, there was a subwoofer in the rear deck; I believe this indicates premium sound system)

I need to tie into the front speakers from behind the factory head unit in order to connect to an amp. It seems impossible to identify which wires are the correct ones. I've found many diagrams, but they are simplified drawings with the wire colors listed. Problem is there are multiple wires of the same color. Can anyone help?

 

I thought the premium came with an amp already built in? If it already had an amp it should be on the pass side in the foot well area.

 

when diagrams aren't available (not common for premium systems), you can pull the speakers to see what wire colors are at each speaker (polarity will be consistent on each speaker). there will be an external amp as mentioned. there will be a harness between the HU and amp. there will be another harness from the amp to the speakers.

sometimes, it is ideal to snag the signal before the factory amp. understanding those wire colors can be a hassle, and require testing. i don't have a diagram for that year/trim.