For 1990-2009 cars

# AM RADIO STATIC ON WEAK STATIONS

AM RADIO STATIC ON WEAK STATIONS-REROUTE POWER ANTENNA HARNESS

#### VEHICLES AFFECTED: 1986-88 CADILLAC BROUGHAMS ------------------

This information supersedes Bulletin 87-8-150, which should be destroyed.

Some 1986-1988 Broughams may exhibit a condition of AM radio static on weak stations. This condition may be caused by voltage induced from the distributor to the harness for the power antenna. This condition may be repaired using the following procedure:

Rerouting the power antenna harness:

1. Disconnect connectors and grounds, items 4 through 11 in Figure 1.

2. Reroute harness as shown in Figure 2.

3. Reconnect connectors and grounds, items 4 through 11 in Figure 1.

4. Use a tie strap, P/N 11509088, to retain harness to brace assembly item 3.

If the static has not been fully removed after following the above procedure, install capacitors on the power antenna circuits. To install the capacitors, follow the procedure below:

Parts Required P/N Quantity -------------- --- -------- Capacitor 1227894 3 Eyelet 2977489 1

1. With the ignition "off", disconnect the negative battery cable.

2. Disconnect the power antenna connector.

3. Backout the terminal for circuit 145, the dark green wire in cavity A, from the antenna side of the connector.

4. Position one lead of capacitor P/N 1227894 (.47 ufd, 200V) to the backside of the terminal crimp. Solder the capacitor lead to the terminal, refer to Figure 3A.

5. Tape capacitor lead to the circuit wire. Be sure to securely wrap tape around capacitor leads so that they are completely insulated, Refer to figure 3B.

6. Reinstall terminal into connector.

7. Repeat steps 3-6 for circuit 161, the gray wire in cavity B.

8. Repeat steps 3-6 for circuit 160, the white wire in cavity C.

9. Gather the three remaining untaped, unsoldered capacitor leads together.

10. Solder 4 ft. length of 18 AWG (.8 metric) wire to the junction of the three capacitor leads.

11. Securely wrap tape around the capacitor leads so that they are completely insulated (including soldered portion of the 4 ft. wire).

12. Solder other end of 4 ft. wire to an eyelet, P/N 2977489 or equivalent, refer to Figure 3C.

13. Attach the eyelet to the braided ground strap at the cowl.

14. Reconnect the power antenna connector and the negative battery cable.

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.