Radio - High Pitched Whine Noise
Article No. 85-10-8RADIO - WHINE - VEHICLES EQUIPPED WITH PREMIUM SOUND AND HEATED BACKLITE
FORD 1984-85 CROWN VICTORIA
LINCOLN-MERCURY 1984-85 GRAND MARQUIS, LINCOLN TOWN CAR
A high frequency engine whine may occur when the engine is running, heated backlite is ON, and the radio volume adjusted to minimum. This can be caused by the heated backlite wires that are parallel to the Premium Sound Amplifier Wires in their routing from the instrument panel to the rear package tray. As a result, the high current heated backlite wires induce the alternator whine into the signal sensitive premium sound wiring, which can then be heard in the radio speakers.
To correct this condition re-route the heated backlite power feed wire (circuit 687) as follows:
1. Pull the knobs from the radio control shafts (1984 radio only - not on 1985 MTR/ETR radio chassis).
Figure 6:
2. Open the ashtray and remove two screws attaching the center finish panel to the instrument panel at the ashtray opening (Figure 6).
3. Pull the lower edge of the center finish panel away from the instrument panel and disengage the upper tabs of the finish panel from the instrument panel.
4. Remove the four screws attaching the climate control assembly to the instrument panel and pull the assembly as far out of the panel as possible.
Figure 7HEATED BACK LITE CONTROL MODULE:
5. Remove the screw retaining the ashtray to the lower instrument panel support brace. Pull the ashtray down exposing the climate control heated backlite control module (Figure 7).
Figure 8 - REAR DEFROST CONTROL TERMINALS:
6. Using a screwdriver, pry up on the climate control connector retainer and remove the connector from the heated backlite control module (Figure 8).
7. Cut the grey with yellow stripe wire (CKT 687) approximately 3 inches from the heated backlite control module (Figure 8).
8. Splice one end of 17 ft. length of PVC covered No. 12 gauge wire to the grey/yellow stripe wire cut in Step 7. Twist the wires and solder securely. Tape the connection using electrical tape. Re-install the connector into the mating receptacle of the heated backlite control module.
9. Route the remaining end of the new wire along the lower I/P support brace to the left side of the vehicle. Retain the wire using tie wraps.
10. Remove the left cowl side cover (one snap) and route wire through the cowl area.
11. Remove the left side wiring trough cover (7 screws) and pull back the carpeting exposing the wiring trough. Remove the cardboard covers and route the wire through the trough.
12. Remove the rear seat and seat back.
13. Remove the 2 screws retaining the lower part of the plastic left side wheel house trim cover to the body sheet metal.
14. Peel the rubber sound deadener away from the wheel exposing the wiring.
15. Route the remaining length of wire through the rear seat strainer into the trunk.
16. Route the wire across the top of the seat back strainer and retain the wire with tie wraps through vacant holes. Keep the wire as far away from the premium sound amplifier and audio wiring as possible.
Figure 9 - Heated Backlite Wire Connector:
17. Locate the heated backlite feed wire connector (blue Figure 9). Cut the grey/yellow stripe wire approximately three inches from the connector and splice the end of the new wire. Twist the wires, solder, and wrap with electrical tape.
18. Check to ensure that the heated backlite works.
19. Replace the components removed in this procedure.
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP18614A85
TIME: 1.3 Hrs. DLR. CODING: Basic Part No. 18A900 - Code: 43