| 1. | Check the No. 36 (10 A) fuse in the under-dash fuse/ relay box. Is the fuse OK? YES - Go to 2. NO - Replace the fuse, and recheck.n |
| 2. | Disconnect the HVAC control unit 24P connector. |
| 3. | Turn the ignition switch ON (II). |
| 4. | Measure the voltage between the HVAC control unit 24P connector terminal No. 23 and body ground.
Is there battery voltage? YES - Go to 5. NO - Repair open in the wire between the No. 36 fuse in the under-dash fuse/relay box and the HVAC control unit.n |
| 5. | Turn the ignition switch OFF. |
| 6. | Check for continuity between the HVAC control unit 24P connector terminal No. 21 and body ground.
Is there continuity? YES - Check for loose wires or poor connections at the HVAC control unit 24P connector. If the connections are good, substitute a known-good HVAC control unit, and recheck. If the symptom/indication is still present, substitute a known-good HVAC control unit, and recheck.n NO - Check for an open in the wire between the HVAC control unit and body ground. If the wire is OK, check for poor ground at G504.n |