Q45 V8-4494cc 4.5L DOHC (VH45) (1992)
Air Conditioning Switch: Description and Operation
A/C Input Signal
When the dash mounted A/C switch is closed, the ECM activates the system by grounding the A/C relay.
Once the A/C system is activated, the ECM will increase the duty cycle of the Idle Air Control-Auxiliary Air Control (IACV-ACC) Valve and stabilize
the idle.