Attachment III

Attachment III

ANTENNA CABLE TESTING PROCEDURE

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 listed 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 as shown:

Blue clip (1) to center pin
Black clip (2) to outside shield.

2) Remove left C-pillar trim panel. Unscrew the antenna lead from the antenna amplifier. Connect the two wires of the U/R/L/G cable as follows:

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:

"M""0""2""1""3""1"".""0""o""o"

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





4) Operate buttons "o""0""6""o". If the insulation between the center wire and the shielding is correct, there will now be a flashing display of 999 k-ohms under 06 RESISTANCE.

5) Reconnect the antenna lead to the amplifier.

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

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