One Door Fails to Lock and Unlock From Any Switch

Test 1 - 3:

Test 4 - 5:

SYMPTOM
ONE DOOR FAILS TO LOCK AND UNLOCK FROM ANY SWITCH

POSSIBLE CAUSES
- Door Lock Motor
- Door Lock Relay Output Circuit Open
- Door Unlock Relay Output Circuit Open
- Door Unlock Relay Output Circuit Short To Ground
- Door Lock Relay Output Circuit Short To Ground