I am trying to install a Factory AM/FM CD player from a 93 Lumina into my 91 Lumina. The main wiring harnesses are identical, however the 93 has a single green wire that is not part of the harness and is connected to a different terminal on the back of the radio. I don't know what this wire goes to? I checked it to see if it was a ground and it isn't. Any help would be greatly appreciated.

I am trying to install a Factory AM/FM CD player from a 93 Lumina into my 91 Lumina. The main wiring harnesses are identical, however the 93 has a single green wire that is not part of the harness and is connected to a different terminal on the back of the radio. I don't know what this wire goes to? I checked it to see if it was a ground and it isn't. Any help would be greatly appreciated.

I would ignore the wire ,,,,tape securely....91-93 uses the same interface conector....

green is the color for left rear speaker...at the radio connector...

That single green wire may be for a power antenna. As noted above, if your '91 does not have one, just tape it off.