Poor and Noisy Reception, Ignition Noise, Missing and Faulty Noise

Poor Reception

^ If vehicle is equipped with power antenna, it must be fully extended.
^ If AM reception is extremely poor and FM reception "spits" or appears to have trouble holding stations, assure that the antenna and antenna connectors are properly mated. If the antenna connectors are properly mated but reception is still poor, replace the antenna cable.
^ If only FM reception is poor, it is unlikely that the antenna is at fault. Remove the radio chassis for service.

NOTE: Many customers do not understand the limitations of FM reception. Refer to Reception Characteristics for informadon about the limitations of AM/FM radio performance.


Noise or static may result from many causes. Two of the most common sources of radio noise are listed below:

Ignition Noise

The most effective method of evaluating ignition noise is to compare the radio performance with engine on, versus engine off. If ignition noise is present with engine running:
- Check Spark plug wires for proper routing, secure connections and continuity. (Especially the coilto-distributor wire).
- Check to see that spark plug wires are the suppresor type and that spark plugs are the correct resistor type.
- Inspect spark plugs and replace any that have cracked insulators.
- Check to see that carbon center insert in distributor cap is secure.
- Check distributor cap and rotor electrodes for silicone grease as they may cause ignition noise on FM or CB. This noise is characterized by a "motor boat" type sound on weak-to-moderate strength stations. Noise can be eliminated only by replacing distributor cap and rotor with a cap and rotor that does not have grease.

NOTE: Silicons grease must not be removed from cars equipped with electronic engine controls (EEC I, EEC II, and EEC III). (Ref. TSB 178 & 186 -Dealer Coding: GREASE Code: 56).

Radio Noise on AM/FM/MPX Radio Chassis All 1983 Vehicles - TSB No. 83-16-7.

Radio Noise on 1984 Lincoln Town Car with Premium Sound option - TSB No. 83-25-6.

Radio Noise F-Series 4.9L Engines, Gauge Package - TSB No. 83-7-17.

Missing or Faulty Noise Suppression

Components

^ Noise suppression components may be faulty or missing. Consult the Shop Manual for correct installation of capacitors, bond straps or other components.
^ Check bond strap grounding effectiveness by wedging a large file between metal parts to insure proper ground, such as between the tailpipe and body, or between the fender and frame, while radio is playing and the engine is running. Listen for decrease in the objectionable radio noise. If a reduction in noise is noted, first try tightening body and exhaust system clamps and brackets. Then, if necessary, install a new bond strap between the two metal parts to insure proper ground.

(Additional information under - TYPICAL ENTERTAINMENT SYSTEM TROUBLESHOOTING TIPS.)