| Subject: | Repeat HVAC Control Head Replacement |
| Models: | 2000 Cadillac Escalade |
| 1995-2002 Chevrolet C/K Trucks |
| 1995-2000 Chevrolet Suburban, Tahoe |
| 1995-2000 GMC Suburban, Yukon |
Updated PI to add to SI2000 and add additional information. Please discard PIA000397.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
You may experience a vehicle where the HVAC control head is In-Operative. After replacing the control head, the vehicle may be back in the dealer several times with the same concern.
Recommendation/Instructions:
Check the following circuits for a short to ground:
- Circuit 66 or Circuit 762 ( Gasoline Engines) Most common area is where the hvac compressor harness comes into the main harness by the left rear cylinder head.
- Circuit 66, Circuit 603 and/or Circuit 762 ( Diesels Engines )
- If a wiring checks out ok, replace the AC Low and/or High pressure switch for internally shorting out to ground.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
