Rear Defogger Inoperative After Rear Window Replacement - keywords aftermarket assembly blown defog factory fuse inop inoperative open window

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

A customer might notice that their rear defogger is inoperative after the rear window has been replaced for whatever reason, This condition is likely caused by a blown (RR-DEFOG) fuse # 23 (30 AMP) in the rear fuse block. Some aftermarket rear windows have been identified as having lower resistance (then the OEM glass) in the defogger grid. This can cause a current overload to occur in the defogger circuit.

When replacing the rear glass assembly make sure it is replaced with OEM GMSPO glass.

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.