Rear

Rear A/C Clutch Relay:

The rear A/C clutch relay for the rear A/C system is an International Standards Organization (ISO)-type relay. Relays conforming to the ISO specifications have common physical dimensions, current capacities, terminal functions and patterns. The rear A/C clutch relay is an electromechanical device that uses a low current input controlled by the rear A/C control module to control the high current output to the A/C clutch field coil for the rear A/C system.

The rear A/C clutch relay is located in the relay block in the rear A/C evaporator housing.

The ISO-standard rear A/C clutch relay is an electromechanical switch that uses a low current input from the rear A/C control module to control the high current output to the rear A/C clutch. The movable, common feed relay contact is held against the fixed, normally closed relay contact by spring pressure. When the electromagnetic relay coil is energized, it draws the movable common feed relay contact away from the fixed, normally closed relay contact and, holds it against the fixed, normally open relay contact. This action allows high current to flow to the A/C clutch field coil.

When the relay coil is de-energized, spring pressure returns the movable relay contact back against the fixed, normally closed contact point. The resistor

or diode is connected in parallel with the relay coil, and helps to dissipate voltage spikes and electromagnetic interference that can be generated as the electromagnetic field of the relay coil collapses.

The rear A/C clutch relay terminals are connected to the vehicle electrical system through a receptacle in the relay block located in the rear A/C evaporator housing.

The rear A/C clutch relay cannot be repaired and, if faulty or damaged, it must be replaced. Refer to the appropriate wiring information for diagnosis and testing of the ISO-standard relay and for complete HVAC wiring diagrams.