Seat Heater Switch Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM: Seat Heater Switch Circuit
- Seat Heater Switch Circuit

DESCRIPTION

Voltage of 5 V is output from the S5-4 terminal of the A/C amplifier to the seat heater SW. The SW4 and SW5 terminals of the A/C amplifier read changes in voltage sent back from the seat heater SW. The voltage sent back from the seat heater SW differs according to the set temperature of the seat heater SW.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT AIR CONDITIONING AMPLIFIER

(a) Remove the A/C amplifier with connectors still connected.





(b) Turn the ignition switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - SEAT HEATER SWITCH)

OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - SEAT HEATER SWITCH)

(a) Disconnect the connector from A/C amplifier.

(b) Disconnect the connector from the seat heater switch.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





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

3. INSPECT SEAT HEATER SWITCH

(a) Connect the 3 dry cell batteries (1.5 V) in series.





(b) Remove the seat heater switch.

(c) Connect the positive (+) lead from the battery to terminal 6 and the negative (-) lead from the battery to terminal 4.

(d) Measure the voltage between terminals 3*1, 1*2 and 4 according to the value(s) in the table below.

Standard Voltage:





*1: Driver side

*2: Front passenger side

NG -- REPLACE SEAT HEATER SWITCH

OK -- REPLACE AIR CONDITIONING AMPLIFIER