Hi guys, I have a 1987 305 TPI that I have retrofit to CCC Qjet form in a 1983 Firebird. I am using a 1984 L69 ECU and wiring. The AC compressor that the 1983/1984 was set up for has the flat 2 prong plug for the clutch. The 1987 AC compressor I am using has the round plug port on the compressor with the 2 pins in it. If I just get the plug end for the 87 compressor from a junkyard car and replace the 2 prong flat plug end with the newer round one, will the 1984 ECU still control the clutch on the newer compressor OK, or is there a fundamental difference in operation that will render them incompatible? I really would hate to not be able to use the newer compressor because the engine has the 1987 brackets/pulleys 100% intact.

 

AFAIK, the ECM does not directly control the AC clutch. On later vehicles, the AC clutch is controlled by the BCM, but still not directly. So long as the connector is changed, and you get the polarity correct, it should work just fine.

 

Vader, the ECM controls an AC relay. You think it will be fine with the 1983 relay controlling the 1987 compressor? It's gotta just be a 12v relay, right?