(1) Set multimeter select switch to
(2) Connect positive (+) multimeter
lead to connector MC15, terminal F.
(3) Connect negative () multimeter
lead to known good ground.
(4) Turn on BLACKOUT LIGHTS
(5) Turn on BLACKOUT MARKER
(6) Turn ON ENGINE switch.
(7) While assistant applies brake pedal,
If 22 to 28 vdc are not present,
perform Steps (8) through (11)
below and go to Step 2 of
If 22 to 28 vdc are present,
wire 1678C is OK. Perform
Steps (8) through (11) below and
go to Trailer Troubleshooting
(8) Release brake pedal.
(9) Turn OFF ENGINE switch.
(10) Turn off BLACKOUT LIGHTS
(11) Turn off BLACKOUT MARKER
Remove all jewelry such as rings, dog tags, bracelets, etc. If jewelry or tools contact positive electrical
circuits, a direct short may result. Damage to equipment, injury or death to personnel may occur.