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:








(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