Antenna Cable - Testing Procedure W/BMW Service Tester

GROUP 65
Radio and Accessories



Bulletin Number
65 09 87 (1460)



Montvale, NJ
August 1987
Technical Dept.



SUBJECT:
Antenna Cable Testing Procedure

MODELS:
All

Situation:
A capacitor for noise suppression is built into the tip of the antenna cable.

This capacitor does not impair radio reception but does reduce noises from the power antenna (while going up) and other outside sources of interference.

If the antenna cable lead is checked for continuity with an ohmmeter it will read open.

For this reason follow the steps on the attached sheet for proper diagnosis of the antenna cable.



^ Remove radio.

^ Pull antenna plug out of radio.


1) Connect the two wires of the FREQ AUS cables. Blue clip (1) to center pin. Black clip (2) to outside shield.


2) Connect the two wires of the U/R/L/G cable.

Red clip (3) to antenna tip.
Black clip (4) to ground.

* 7351 with rear window antenna - unscrew the antenna lead from the antenna amplifier.

With a suitable probe connect the red clip to the center wire and the black clip to the outside shield.






3) In the sequence shown operate these buttons on the BMW Service Tester.






If the antenna lead is intact, the voltage displayed under 02 U-AC will be greater than 0.4V.



999 k-ohms under 06 RESISTANCE.



5) Now disconnect lead U/R/L/G at the antenna and connect the red clip to the outside shield (5) of the antenna plug in the passenger compartment and the black clip on car ground point (6).

* 7351 with rear window antenna - reconnect the antenna lead to the amplifier before performing this test step.



The value displayed under 06 RESISTANCE should be less than 0.5 ohm, if the antenna has a proper ground connection. If a higher reading is obtained, check the grounding of the antenna.