Radio - AM Interference From Interior Lights/Accessories

9215bmw02

Group 65
Radio and
Accessories


Bulletin Number
65 12 91 (3384)


Woodcliff Lake, NJ
January 1992
Product Engineering


SUBJECT: AM Radio Interference from Interior Lights and Accessories

MODELS: 3 Series (E36), 5 Series (E34)


Situation: Complaints of clicking or popping noises from the radio in the AM range associated with switching ON or OFF interior lights, rear window defogger, and other electric accessories. Interference may also be noticed when interior lights are dimmed or faded-out.

Solution: Two capacitors must be installed on the antenna amplifier, as well re-routing some wiring to prevent interference (see illustration).

Procedure: 1. Remove the driver's side "C" pillar trim and unbolt the antenna amplifier.
2. Clip the connector off of the lead on the 4.7 uF capacitor (P/N 65 81 1 370 418) and strip about 3/8" of insulation.
3. Remove the black defogger connection from the antenna amplifier. Clip off the female spade terminal and strip about 3/8" of insulation.
4. Crimp both the defogger lead and the 4.7 uF capacitor lead in a new female spade terminal (P/N 81 24 9 408 335) and insulate with a new lock housing (P/N 81 24 9 408 336).








5. Remount the antenna amplifier with the 4.7 uF (P/N 65 81 1 370 418) and
47 uF (P/N 65 31 1 357 878) capacitors in place (see illustration). The
4.7 uF capacitor mounting tab must go under the mounting flange on the
antenna amplifier in order to fit properly.
6. Reconnect the modified defogger terminal to the antenna amplifier.
7. Disconnect the electrical connector for the interior light, and remove the brown/red wire socket from the connector with a 2.5 mm terminal extraction tool (61 1 150). Cut off the socket from the brown/red wire and strip about 3/8" insulation.
8. Obtain a 14" piece of similar wire, and strip about 3/8" off of both ends.
Crimp one end of the wire along with the brown/red interior light wire in a new socket (P/N 81 24 9 408 415).
9. Crimp the free end of the 14" wire in a male spade terminal
(P/N 81 24 9 408 108) and connect to the female spade terminal of the .47 uF capacitor (P/N 65 31 1 357 878).
10. Insulate this connection with electrical tape or shrink tubing.


11. Install the new brown/red wire socket in the old connector housing, and plug the connector into the interior light.
12. Check the routing of the interior light wires and the AM/FM antenna leads from the antenna amplifier to the antenna/defogger grid. Tape interior light wires to the inside edge of the "C" pillar trim. Tape the AM/FM antenna leads between the antenna amplifier and the rear glass. See illustration for preferred wire locations.

Parts
Information: Part Number Description

65 31 1 357 878 .47 uF capacitor
65 81 1 370 418 4.7 uF capacitor

81 24 9 408 335 Female spade terminal
81 24 9 408 336 Lock housing

81 24 9 408 108 Male spade terminal

81 24 9 408 415 2.5 mm socket terminal

Warranty
Status: Covered under the terms of the applicable BMW New Car Limited Warranty.

Defect code: 65 31 00 12 00

Labor operation: 00 50 193 (install capacitors)

Labor allowance: 7 FRU