Rear

Rear Blower Motor Relays:

The three rear blower motor relays used for the rear A/C system are International Standards Organization (ISO)-type relays. Relays conforming to the ISO specifications have common physical dimensions, current capacities, terminal functions and patterns. The rear blower motor relays are electromechanical devices that switches fused battery current directly to the rear blower motors. The rear blower motor relays are energized when the relay coils are provided battery current by the rear blower motor switch.

The rear blower motor relays are located in the relay block in the rear A/C evaporator housing.

The three ISO-standard rear blower motor relays are electromechanical switches that uses a low current input from the rear blower motor switch to control the high current output to the rear blower motors. 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 rear blower motors.

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 blower motor relay terminals are connected to the vehicle electrical system through receptacles in the relay block located in the rear A/C evaporator housing.

The rear blower motor relays cannot be repaired and, if faulty or damaged, they must be replaced. Refer to the appropriate wiring information for diagnosis and testing of the ISO-standard relay and for complete HVAC wiring diagrams.