Antenna - Power Chevrolet Camaro II

DESCRIPTION

Power antenna used on General Motors vehicles are one of two types: An AM/FM type and a tri-band type (AM/FM/CB). The antenna automatically raises to full height whenever radio and ignition are turned on. Antenna retracts to fender when either radio or ignition is turned off.

Drive unit is encased in a 2-piece plastic housing attached to mast and tube assembly. A permanent magnet motor with worm drives move the antenna up and down. A plastic cable is attached to upper mast section. Upper and lower travel limits are controlled by switches opened by armature shaft thrust as mast reaches end of its travel. A circuit breaker is used to prevent motor from overheating.

The tri-band antenna has a load coil mounted on center mast section for CB radio tuning. There is no on-car service of the AM/FM antenna other than cleaning mast section. The load coil and tip are serviceable on tri-band antennas.

Exploded View of GM Power Antenna Tri-Band antenna shown, others similar. Scheme 1

ANTENNA DOESN'T RAISE OR LOWER

Check for blown fuse, loose electrical connections on receiver or antenna, bent antenna mast or a malfunctioning relay. See Testing.

WEAK RECEPTION OR FADING

Moisture in support tube from condensation or leakage. Antenna must be removed, disassembled and drive housing cleaned or replaced.

EXCESS IGNITION NOISE, ERRATIC AUDIO OR REDUCED CB RECEPTION

Poor grounding of antenna at mounting or at lead-in system. Antenna ground must be checked as described in Testing.

PRELIMINARY CHECK

1. Unplug antenna lead at back of radio and plug in a known good antenna. Ground test antenna and keep hands off mast. Check reception in an area away from electrical interference.
2. Tune radio to high and low ends of dial in both AM and FM bands. If reception is okay, a problem exists with antenna and/or lead-in cable. If reception is still poor, check radio for problems.

LEAD-IN CABLE CHECK

Usually symptoms of broken center conductor of lead-in cable will result in no AM and weak FM reception. In cases of continued reception problems, always check lead-in with an ohmmeter. Use the resistance chart for test results. When checking resistance, carefully wiggle the lead-in tip and cable. If results are not as listed in chart, the lead-in should be replaced.

Lead-In Resistance Check Points Connect ohmmeter between test points in chart. Scheme 2

LEAD-IN CABLE RESISTANCE

GROUND CHECK

1. Fully lower antenna. Remove escutcheon from fender. Attach alligator clip to upper end of mast to act as antenna. Leave other end of clip unattached.
2. Tune radio to a weak AM station, or a station which is received through alligator clip. Remove the clip. Ground the upper end of the mast to the fender.
3. If the same station is not received, the grounds are good, and no further action is necessary. If the station is still present, or even stronger, a poor ground or no ground condition exists.
4. Possible ground loss points are: Antenna upper mounting (screw loose, paint overspray), coaxial connector at mast not connected or corroded, coaxial connector at radio not tight or corroded, quick connector corroded, loose matching stub connection on CB only or a problem in splitter coaxial crimp on AM or CB lead only.

ANTENNA DOES NOT FULLY RAISE OR LOWER

1. If motor operates, pull up on top section of mast. If mast moves freely, plastic drive cable is broken. Replace mast and support tube. If cable is not broken, remove mast and support tube. Check mast sections for binding.
2. If binds exist, eliminate binding or replace mast and support tube. If no binding, check drive cable for broken hook. If no breaks, replace gear and spool assembly.

ANTENNA DOES NOT LOWER

1. If the motor does not run, and antenna will not lower, check fuse in fuse block. If fuse blown, remove relay and install new fuse. If fuse blows again, repair short in Org/Blk wire. If fuse does not blow, check for short in White wire. If no short, replace relay. If White wire shorted, repair wire. If no short, repair antenna motor.
2. If the fuse was okay in original check, use test lamp and check for 12 volts at Org/Blk wire at antenna relay. If lamp does not light, repair open in Org/Blk wire. If lamp lights, check for voltage at White wire on relay.
3. If lamp does not light, replace antenna relay. If lamp lights, check for open in White wire. If no open, check for voltage at Dk. Green wire. If lamp lights, check relay connections and ground wire. If both okay, replace relay. If lamp does not light, check for loose connection between relay and connector or connector to antenna. If okay, repair motor.

ANTENNA DOES NOT RAISE

1. If motor does not run, check fuses in fuse block. If radio fuse is blown, repair radio. If antenna fuse is blown, remove antenna relay, install new fuse and recheck. If fuse is okay, check for short in Green wire. If no short, replace relay. If shorted, check Grey wire for opens. If okay, repair motor. If new fuse installed blows, repair short in Org/Blk wire from fuse panel to connector.
2. If fuses were okay in original check, turn ignition off. Connect test light to Org/Blk wire at relay connector. If lamp does not light, repair open in Org/Blk wire. If lamp lights, turn ignition and radio on and listen for relay click. If relay does not click, check for open relay ground, open in Pink wire, or bad radio switch (probe Pink wire, if voltage exists, replace relay).
3. If relay clicked in above step, check for voltage at Dk. Green wire in relay connector. If lamp does not light, replace relay. If lamp lights, check for voltage at Grey wire. If lamp lights, check relay connections and ground wire.If okay, replace relay. If lamp does not light at Grey wire, check for open or short in Grey and Dk. Green wires. If okay, repair motor.

Note. The following procedure is general for all vehicles, not all steps apply to all models.

Removal

1. Disconnect negative battery cable. Turn steering wheel to full right or left stop, depending on which fender antenna is mounted. Remove fender inner splash shield. Remove instrument panel sound absorber.
2. Disconnect antenna lead-in connector from radio, then from antenna relay. Remove antenna-to-fender attaching retainers. Remove tire and wheel if necessary to gain access under fender. Remove inner fender supports.
3. Remove antenna bracket bolts, or lower antenna attaching screws. On Cadillac RWD models, attach a four-foot guide wire to top of antenna to help guide mast sections out of housing. On all other models, with all wiring disconnected, gently guide wires and antenna through fender opening.

Installation

To install, reverse removal procedures. On Cadillac RWD, use guide wire to guide new antenna into housing.