To improve the time to clear heavy condensation or frost from the inner or outer surfaces of the windshield during periods of high humidity/low temperature ambient conditions, the owner should be aware of the owner's manual operating instructions regarding the use of the ventilation, heater and air conditioning system. It is particularly important that the air-source select lever usage is fully explained, since improper use of this lever can cause a complaint condition.
In the event of the complaint condition existing with the correct usage of the heater controls, the right and left hand defrost ducts (nozzles) should be replaced using the 1987 components following the Shop Manual procedures:
P/N 94436981 Nozzle Defrost R.H. P/N 94436982 Nozzle Defrost L.H.
These parts incorporate changes to the deflector locations and angles which result in more effective distribution of the heated air over the windshield.
Labor Operation Number: T1213 Labor Time: 1.9 Hours
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.