PTC Heater Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM: PTC Heater Circuit
- PTC Heater Circuit

DESCRIPTION

The GLW RLY turns on when it receives a signal from the A/C amplifier. As a result, power is supplied to the heater glow plug.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (LH-IG, GLW PLG1, GLW PLG2)

(a) Remove the LH-IG fuse from the cowl side J/B LH.





(b) Remove the GLW PLG1 and GLW PLG2 fuses from the engine room R/B and J/B No. 1.





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

Standard resistance:





NG -- REPLACE FUSE
OK -- Continue to next step.

2. INSPECT RELAY (GLW RLY1, GLW RLY2)

(a) Remove the GLW RLY1 and GLW RLY2 relays from the engine room R/B and J/B No. 1.





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

Standard resistance:





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

3. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY)

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





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

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

Standard voltage:





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

4. INSPECT AIR CONDITIONING AMPLIFIER

(a) Reconnect the connector to the A/C amplifier.





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

Standard voltage:





NG -- REPLACE AIR CONDITIONING AMPLIFIER
OK -- Continue to next step.

5. INSPECT HEATER BLOWER WIRE

(a) Remove the grommets and nuts of the water by-pass glow plugs.

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

(c) Perform Active Test by referring to the table below.

Active Test / Air Conditioner:

Active Test / Air Conditioner::

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





Standard voltage:





NG -- REPAIR OR REPLACE HEATER BLOWER WIRE
OK -- Continue to next step.

6. INSPECT WATER BY-PASS GLOW PLUG

(a) Remove the water by-pass glow plug.





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

Standard resistance:

Below 1 Ohms

NG -- REPLACE WATER BY-PASS GLOW PLUG

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