Wiring Diagram. Terminal 86 = 12V trigger. Terminal 85 = Ground trigger. ... For instance, most late-model GMs use Bosch relays, which PSI Conversions uses exclusively.

These two wires are easily seen in a wiring diagram of the vehicle. Mike, your wire color should be dark blue and the purple. Check to see if these wires have 12 volts at the mass air flow sensor ...