Cherokee 2WD L6-242 4.0L VIN L FI (1990)
Compressor Clutch Relay: Description and Operation
Relay Cluster Location -- On Right Front Wheel Well
The ECU uses this relay to control the air conditioning compressor clutch. When air conditioning is turned on in the vehicle, the A/C evaporator switch
will send a signal to the ECU and the ECU will send a signal to the idle speed stepper motor and it will adjust itself to increase the idle speed. After the
idle speed increases, then the A/C compressor clutch relay will energize which will send voltage to and engage the A/C compressor clutch.
It is important that the ECU adjust the idle speed stepper motor to increase the engine speed due to the increased engine load from the A/C compressor
could be enough to stall the vehicle if the engine speed is not high enough.