GM Service Manual Online
For 1990-2009 cars only

The main relay mounts on a bracket. The bracket is bolted onto the right hand side of the heater case.

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Pull out the instrument panel compartment while pushing the stopper from both the left and right sides.
  3. Remove the 2 screws and the relay mounting bracket from the heater case.
  4. Release the locking tab in order to remove the main relay from the mounting bracket.
  5. Disconnect the main relay electrical connector (5).
  6. Remove the main relay from the vehicle.

Installation Procedure

  1. Connect the main relay electrical connector (s).
  2. Install the main relay to the mounting bracket.
  3. Install the relay mounting bracket to the heater case. Secure the bracket with the 2 screws.
  4. Close the instrument panel compartment.
  5. Connect the negative battery cable.