DECISION
Petcock(s) open - Test 6 - Does buzzer stop, and air indicator light extinguish?
Petcock's closed - Test 3 - Is trailer air supply control in correct position?
TEST 3 - Is trailer air supply control in correct position?
1.
Check that trailer air supply control is pulled out (OFF position) if no trailer is coupled,
and pushed in (ON position) if trailer is coupled.
2.
If trailer air control is found in an incorrect position, set to correct position.