Test A: The Navigation System Is Inoperative

PINPOINT TEST A: THE NAVIGATION SYSTEM IS INOPERATIVE

A1-A2:

A2-A4:

A5:

Normal Operation
The audio unit receives voltage on circuits 137 (YE/BK), 1786 (BN/PK) and 956 (OG/LG) and is grounded by circuit 694 (BK/LG).

Possible Causes
- circuit 137 (YE/BK) open
- circuit 956 (OG/LG) open
- circuit 694 (BK/LG) open
- audio unit