Some vehicles may experience a condition of a loss of air delivery with blower still operating. This condition will only occur after the vehicle has been driven several miles. This condition may be caused by a shorted compressor cycling switch, which results in the evaporator core freezing up and blocking all air flow through the evaporator case. To repair this condition, check to see if the compressor cycles on and off with the A/C on. If the compressor does not cycle off, check for a shorted compressor cycling switch and replace the cycling switch if it is shorted.
For warranty purposes, use Labor Operation D1140 at:
.2 hour for 1981-1985 RWD DeVilles and Broughams .3 hour for 1986-1987 RWD Breougham .3 hour for Eldorados and Sevilles
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.