Assuming I had a 1990-1992 SD harness in a 92 Camaro and it needed a lot of repairs and was looking for a replacement. Does it have to be from a Camaro or would a SD harness from a Pontiac work as well? I understand the battery is on the opposite side on the Pontiac but I think that is a separate connection?

 

It should be the same aside from the location of the battery, and thus, the inline ECM/fuel pump fuse. The body harness would be different yet, with the battery difference and the presence of headlight motor and fog lamp relays on the Firebird.