Rubidon

iTrader: (1)

I am using a wiring harness out of a 2002 silverado for my swap and I can not figure out where the gray wire goes from the Engine Coolant Temp sensor. The yellow wire goes to C1 Blue 74, but I get different spots for the gray wire, some say 80 or 63 ?

poconojoe

iTrader: (43)

It depends on if you have isolated ground O2 sensors, if you do, the isolated ground wire from the O2 sensor uses pin 63, and you'd have to use pin 80 as the low referance

Rubidon

iTrader: (1)

How would I know that from the wiring harness? The low reference is referring to the gray wire?