No Sound From All Speakers

Tests 1 - 3:

Tests 4 - 8:

Tests 9 - 12:

Tests 13 - 14:

SYMPTOM
NO SOUND FROM ALL SPEAKERS

POSSIBLE CAUSES
- Intermittent short - fuse # 18 or # 19
- Fused B+ circuit short to ground
- Intermittent short - fuse # 4
- Radio - fused ignition switch output circuit shorted
- Fused ignition switch output circuit shorted to ground
- Open fused B+ circuit to radio
- Open fused ignition switch output CKT to radio
- Open radio ground circuit
- Open fused B+ circuit to power amplifier
- Open ground circuit to power amplifier
- Open radio 12V output circuit to amplifier
- Radio 12V output circuit shorted to ground
- Radio (no speaker output)
- Radio (no radio 12V output)
- Power amplifier (no output)