How to Proceed with Troubleshooting
HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Manual Air Conditioning System): Heater Control Switch Circuit
- Heater Control Switch Circuit
DESCRIPTION
The No. 3 heater control is powered through the HTR-IG fuse. The No. 3 heater control transmits operational signals of each switch to the A/C amplifier.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. INSPECT FUSE (HTR-IG)
(a) Remove the HTR-IG fuse from the instrument panel junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPLACE FUSE (HTR-IG)
OK -- Continue to next step.
2. INSPECT NO. 3 HEATER CONTROL
(a) Measure the resistance.
(1) Remove the No. 3 heater control.
(2) Disconnect the connector from the No. 3 heater control.
(3) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
*1: w/ PTC heater
(b) Check that the indicator light comes on.
(1) Connect a positive (+) lead from the battery to terminal 3 and a negative (-) lead from the battery to terminal 4, and check that the indicator light comes on.
OK:
The indicator light comes on.
(c) Check that the illumination comes on.
(1) Connect a positive (+) lead from the battery to terminal 5 and a negative (-) lead from the battery to terminal 6, and check that the illumination comes on.
OK:
The illumination comes on.
NG -- REPLACE NO. 3 HEATER CONTROL
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (NO. 3 HEATER CONTROL - BATTERY)
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
HINT
*1: w/ PTC heater
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (NO. 3 HEATER CONTROL - A/C AMPLIFIER)
(a) Disconnect the connector from the A/C amplifier.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
*1: w/ PTC heater
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures