1. Check for continuity between the HFT-voice control switch 5P connector terminal No. 2 and the audio unit connector A (20P) terminal No. 11.

Is there continuity?

YES | - | Check for loose or poor connections at the audio unit, hands free telephone control unit, and HFT-voice control switch. If the connections are OK, substitute a known-good hands free telephone control unit. If the problem is gone, replace the original control unit.■
NO | - | Repair open in the wire between the switch, cable reel, and the audio unit.■