A/C FLUTTER NOISE AT HIGH- BLOWER- ALLANTE (REPAIR)

MODELS AFFECTED: 1987 ALLANTE

Some 1987 Allantes built prior to VIN 102526 may exhibit a fluttering noise from the A/C ducts at high blower speed. This noise is caused by the rubber seal of the up-down valve (door) vibrating against its lower seat. To repair this condition, use the following procedure:

1. Start car and set the up-down lever to the "DOWN" position. This will command the up-down valve (door) to its "UP" position, sealing off air to the A/C ducts. to the A/C ducts.

2. Turn the ignition to the "OFF" position.

3. Remove the passenger side hush panel.

4. Inspect A/C module. Some vehicles may have no retainer, a retainer installed upside down, or a retainer installed in the wrong location. See Figure 1 for correct location.

5. Drill a 7/32" hole in the module as indicated in Figure 1. If the vehicle has an incorrectly installed retainer preventing drilling of the 7/23" hole in the prescribed location, move forward or rearward maintaining a distance of 30mm from the A/C module contour.

6. Trim the head of the retainer, P/N 00411700, as indicated in Figure 2 to allow a correct fit along the edge of the heater duct.

7. Install retainer by pressing upward into HVAC module.

For warranty purposes, use Labor Operation T6255 for .3 hour.

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.