Heater Relay Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM: Heater Relay Circuit

Heater Relay Circuit

DESCRIPTION

The heater relay is turned on by signals from the air conditioning amplifier. It supplies power to the blower motor controller.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (GAUGE, HTR)
(a) Remove the GAUGE fuse from the driver side junction block.
(b) Remove the HTR H-fuse from the engine room junction block.
(c) Measure the resistance of the fuses.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.

2. INSPECT HEATER RELAY (Marking: HTR)




(a) Remove the heater relay from the driver side junction block.
(b) Measure the resistance of the relay.
Standard resistance:






NG -- REPLACE HEATER RELAY
OK -- Continue to next step.

3. CHECK WIRE HARNESS (BATTERY - AIR CONDITIONING AMPLIFIER)




(a) Disconnect the A8 amplifier connector.
(b) Measure the voltage of the wire harness side connector.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

4. CHECK AIR CONDITIONING AMPLIFIER (HR VOLTAGE)




(a) Remove the air conditioning amplifier with connectors still connected.
(b) Measure the voltage of the connector.
Standard voltage:






NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE