70s GM Radio Installation Question

[Q8]

Well, I already had them reaplaced when I hd the car in the shop last. The dash hs nice new pioneer 2-way speakers. But now I need to figure out where the speaker harness meets the radio harness. Right now I have nice new speakers on an AM radio. As I said before, the car has a stereo dash, but the person that originally purchased the car opted for AM only.