The AC has to be controled by the stock ecu. The stock ecu cycles the AC compressor on an off. I'm running a TEC 3 in a '91 miata chassis on a 2002 motor. The only signal that the stock ecu needs to control the AC, in my case, is the cam angle sensor. I'm not sure if you have cam angle sensor or a distributor but the distributor signal to the ecu should have the same effect.