PTC Heater Circuit

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Manual Air Conditioning System): PTC Heater Circuit
- PTC Heater Circuit

DESCRIPTION

PTC heater relays are closed in accordance with signals from the air conditioning amplifier assembly and power is supplied to the quick heater assembly installed on the radiator heater unit.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. INSPECT PTC HEATER RELAY (PTC NO. 1, PTC NO. 2, PTC NO. 3)

(a) Remove the PTC NO. 1 relay from the engine room No. 1 relay block, junction block.

(b) Remove the PTC NO. 2 and PTC NO. 3 relays from the engine room No. 2 relay block.

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

Standard Resistance:

NG -- REPLACE PTC HEATER RELAY (PTC NO. 1, PTC NO. 2, PTC NO. 3)
OK -- Continue to next step.

2. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Remove the air conditioning amplifier assembly with its connectors still connected Removal.

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

Standard Voltage:

Text in Illustration

HINT
*: After the measurement conditions are met, wait 30 seconds before performing measurements.

NG -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Air Conditioning System (for Manual Air Conditioning System)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK, JUNCTION BLOCK - AIR CONDITIONING AMPLIFIER)

(a) Remove the PTC NO. 1 relay from the engine room No. 1 relay block, junction block.

(b) Disconnect the F42 amplifier connector.

(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.

4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - AIR CONDITIONING AMPLIFIER)

(a) Remove the PTC NO. 2 and PTC NO. 3 relays from the engine room No. 2 relay block.

(b) Disconnect the F42 amplifier connector.

(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.

5. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK, JUNCTION BLOCK - QUICK HEATER)

(a) Remove the PTC NO. 1 relay from the engine room No. 1 relay block, junction block.

(b) Disconnect the F85 heater connector.

(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.

6. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - QUICK HEATER)

(a) Remove the PTC NO. 2 and PTC NO. 3 relays from the engine room No. 2 relay block.

(b) Disconnect the F85 heater connector.

(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.

7. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK, JUNCTION BLOCK - BATTERY AND BODY GROUND)

(a) Remove the PTC NO. 1 relay from the engine room No. 1 relay block, junction block.

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

Standard Voltage:

Text in Illustration

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

8. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - BATTERY AND BODY GROUND)

(a) Remove the PTC NO. 2 and PTC NO. 3 relays from the engine room No. 2 relay block.

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

Standard Voltage:

Text in Illustration

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

9. INSPECT QUICK HEATER ASSEMBLY

(a) Remove the quick heater assembly Removal.

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

Standard Resistance:

NG -- REPLACE QUICK HEATER ASSEMBLY Removal
OK -- Continue to next step.

10. CHECK HARNESS AND CONNECTOR (QUICK HEATER - BODY GROUND)

(a) Disconnect the F86 heater connector.

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

Standard Resistance:

Text in Illustration

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)