NO AM RECEPTION WITH REPLACEMENT POWER ANTENNA MAST
When replacing a power antenna mast and support tube using the original threaded lead-in (RF cable), it will be necessary to use RF housing kit, P/N 22038652, in place of the original RF housing and screw. This is necessary to obtain a proper RF connection when the lead-in is installed. The RF pin supplied with the mast and support tube will be too short when used with the original threaded RF housing. Be sure that screws do not contact the mast inside the support tube when fully seated as this could short circuit the antenna. A check with an ohmmeter from mast to the support tube should show infinite resistance or open circuit. A check from the lead-in center conductor for continuity to the mast should be "0" ohms. Using the new RF housing in kit, P/N 22038652, will ensure a good contact. Be sure to use a liberal amount of the grease, supplied in the kit, to prevent water entry. Refer to figure below.
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.