My 92 Buick Regal Air Conditioning is not working. Specifically, the A/C
relay is not getting a signal to turn on the relay, which energizes the
compressor clutch. The compressor and clutch are working fine - when I
remove the relay and jumper across the pins for the relay contacts, the
clutch engages, and the A/C works.
I see on the wiring diagram that the A/C relay is supposed to get its signal
from pin 7 of the ECV, so I would like to measure directly on pin 7 of the
ECV - but where the heck is the ECV, and how do I tell which is pin 7?
Also, what signals are given to the ECV to have it determine the A/C relay
signal, i.e. whether to engage the compressor clutch? Are there sensors
somewhere that should be checked?