Harness Connections

BE SURE to remove the ECM from the harness connectors before doing any circuit testing or modifications AND be sure to solder ALL harness connections. Use only the original GM type relays as they have built-in diodes to eliminate problems with voltage spikes. Along this same line, when wiring the A.C. Compressor be sure to use a GM-type twin pin electrical connector as these are also equipped with a diode, wired between the two terminals. These diode equipped A.C. Compressor electrical connectors can be found on any late GM vehicle with an ECM controlled carburettor/fuel injection system.

Mounting Brackets

GM uses a plastic mounting bracket to mount the ECM in the vehicle. If your system does not have one attached to the ECM when you get it, this bracket can be ordered under GM #14073420.

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