If an owner comments of temperature overshoot on a 1987 LeSabre of Electra with C68 built before December, 1986; the cause may be partial or complete blockage of the in-car temperature sensor openings in the instrument panel pad.
Visually inspect to see if the two openings for the sensor are visible in the underside of the instrument panel pad top lip. If blocked by the right upper instrument panel accessory trim plate, perform the following steps:
Remove center and right Air Conditioning (A/C) outlets.
Remove six (6) screws that hold right accessory trim plate.
Obtain new trim plate and remove portion of 13" long foam strip from back side. Foam strip need only be removed if it is first type that is 13" x 1/2" in size. Remove portion of the foam with sharp cutting edge to decrease foam thickness to approximately 1/8".
Replace emblem or name plate as required.
Install new trim plate and check A/C system operation.
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.