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 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:
### ptxt ### *1: w/ PTC Heater Assembly
(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.
Text in Illustration
NG -- REPLACE NO. 3 HEATER CONTROL Disassembly
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (NO. 3 HEATER CONTROL - BATTERY)
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
*1: w/ PTC Heater Assembly
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. 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:
*1: w/ PTC Heater Assembly
*2: except TMC Made 2AZ-FE
*3: for TMC Made and except TMC Made 2ZR-FE
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Air Conditioning System (for Manual Air Conditioning System)