Attachment II
Attachment IIANTENNA/ANTENNA AMPLIFIER DIAGNOSIS
General Information:
Use the diagram for reference. The gridwork in the rear window consists of 19 separate lines in 3 groups.
^ upper 3 lines - AM only
^ middle 8 lines - FMIWB and rear defogger
^ lower 8 lines - rear defogger only
Gridwork Diagnosis:
1) Remove cover from left C-pillar.
2) Disconnect the wire at the amplifier labeled AM. Connect one lead of an ohmmeter to this wire going to the grid.
3) Using the other ohmmeter lead as a probe, check along the entire width of the upper 3 lines individually for continuity, repairing any breaks found.
4) If all 3 lines indicate opens, check for proper connection of the AM wire to the grid.
An improper connection can be repaired using low temperature solder.
5) Disconnect the wire of the amplifier labeled FM. Check for proper con necti of this wire to the grid using an ohmmeter connected between the grid and the removed FM wire at the amplifier. Repair if needed using low temperature solder.
6) Start engine and turn ON rear defogger.
7) Connect the negative lead of a voltmeter to suitable ground and use the positive lead as a probe to check the middle 8 lines as follows:
^ Starting on the left side of the window, move the probe across a grid line to the right side of the window.
^ The voltage should be approximately 12V on the left hand side and drop gradually to 0 volts while moving the probe to the right side. Repeat this procedure on the remaining 7 lines in the middle grid.
^ A reading of approximately 13V indicates an opening in that grid line. Move the probe across the affected line until the voltage drops to 0 volts. This indicates the area of the grid that is damaged. Repair brea
8) Turn ignition OFF and connect removed wires to antenna amplifier.
Gridwork Repair:
Breaks in the gridwork can be repaired using Repair Kit Part No.81 22 9 407 066.
Antenna Amplifier Diagnosis:
1) Turn ignition ON and manually turn the radio to a weak AM or FM station.
2) Remove the white wire (amplifier power supply) from the antenna amplifier. A noticeable loss of reception should be apparent.
3) If no change is heard check for 12V at this white wire. Repair vehicle wiring 12V is not present.
Note: This wire goes to the radio's "antenna up" output.
4) If 12V is present install a new antenna amplifier.
Note: Amplifier must be mounted to C-pillar for proper grounding.
5) Repeat Steps 1 and 2.
If problem is still present, the amplifier is not defective. Reinstall original amplifier and look for problems in the antenna cable or radio.