Display Does Not Dim or Brighten With Dimmer

Symptom Troubleshooting: Display does not dim or brighten with dimmer

Display does not dim or brighten with dimmer

NOTE:

- Check the connectors for poor connections or loose terminals.

- Check the vehicle battery condition first.

1. Turn the ignition switch to ON (II).

2. Turn the headlight switch to the parking or headlight on position.

3. Check the display of the climate control unit.

Does the climate control illumination change with dimmer?
YES - Go to step 4.

NO - Go to climate control power and ground circuit troubleshooting. Testing and Inspection


4. Check the No. 7 (10 A) fuse and the No. 32 (10 A) fuse in the under-dash fuse/relay box.

Are the fuses OK?
YES - Go to step 5.

NO - Replace the fuse, and recheck.


5. Remove the audio unit. Audio Unit Removal/Installation Check that the audio unit and climate control unit connectors are properly connected.

Are they connected properly?
YES - Go to step 6.

NO - Repair poor connections and reconnect the connector, and recheck the function.


6. Turn the ignition switch to LOCK (0).

7. Disconnect audio unit connector C (24P) and climate control unit connector B (14P).

8. Check for continuity between the audio unit connector C (24P) terminal No. 24 and climate control unit connector B (14P) terminal No. 8.

Is there continuity?
YES - Go to step 9.

NO - Repair open in the wire between the audio unit connector C (24P) terminal No. 24 and climate control unit connector B (14P) terminal No. 8.






9. Check for continuity between the body ground and audio unit connector C (24P) terminal No. 24.

Is there continuity?
YES - Repair short to body ground in the wire(s) between the audio unit and climate control unit.

NO - Go to step 10.






10. Disconnect climate control unit connector A (40P).

11. Measure the voltage between terminal No. 1 of climate control unit connector A (40P) and body ground.

Is there battery voltage?
YES - Go to step 12.

NO - Repair open in the wire(s) between the No. 7 (10 A) fuse in the under-dash fuse/relay box and the climate control unit.






12. Turn the ignition switch to ON (II).

13. Measure the voltage between terminal No. 25 of climate control unit connector A (40P) and body ground.

Is there battery voltage?
YES - Go to step 14.

NO - Repair open in the wire(s) between the 32 (10 A) fuse in the under-dash fuse/relay box and the climate control unit.






14. Turn the ignition switch to LOCK (0).

15. Reconnect the audio unit connector A (17P).

16. Turn the ignition switch to ON (II).

17. Measure the voltage between climate control unit connector A (40P) terminal No. 37 and body ground.

Is there less than 0.1 V?
YES - Substitute a known-good climate control unit, and recheck. If the symptom/indicated goes away, replace the original climate control unit. If the symptom is still present, substitute a known-good audio unit, and recheck If the symptom/indicated goes away, replace the original audio unit. Audio Unit Removal/Installation

NO - Repair open in the wire between the climate control unit connector A (40P) terminal No 37 and body ground (G506).