Customers transferring the Cadillac factory garage door opener from a 1988 Cadillac to a 1989 or 1990 DeVille or Fleetwood with heated windshield may experience reduced garage door opener operating range. The range may be reduced by up to 50%
Reduced range on the Electriclear equipped cars is caused by the transparent metallic heating film between the layers of the windshield glass. The garage door opener transmitter signal is weakened as it passes through the metal heating film.
Customers may wish to refer to the 1989 or 1990 DeVille/Fleetwood Owner's Manual, under "Garage Door Opener (option)" and also under "Heated Windshield (option)", for commentary on heated windshield and its effects on garage door openers, radar detectors, and other radio receivers/transmitters using signals which pass through the windshield.
To improve the garage door opener range, have the customer check receiver mounting location. For best results the receiver should be mounted so the antenna has minimal interference from metal objects between the car and the receiver antenna. Some receivers which were mounted behind metal garage doors or in the back of the garage may have to be moved. It may help to extend the small metal receiver antenna by attaching a length of wire.
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.