Check ground lead for continuity as follows:
Disconnect wiring harness from towing
Disconnect ground lead (black) from
back of each light assembly (para 4-16).
Connect multimeter red lead to harness
connector pin D. Connect black lead to
end of ground lead.
continuity is not present, replace
wiring harness (para 4-17). If
continuity is present, reconnect
Check all electrical leads for continuity as
Remove lens and lamps from each light
assembly (para 4-16).
The only wires used are the ones illustrated.
All other wires are cut.
Refer to wiring diagram. Check each
lead for continuity.
continuity Is not present in any lead,
replace wiring harness (para 417). If
continuity Is present in all leads,
replace light assembly (para 4-16).
ONE OR MORE (BUT NOT ALL) LIGHTS FAIL TO
Replace inoperative lamp (para 4-16).
of lamp. If lamp does not operate,
continue with this troubleshooting
Check wiring harness for loose connections
and broken wires.
connections. Replace or repair wiring
harness (para 4-17).
Disconnect wiring harness plug and check for
loose, dirty, or corroded contacts.
Dry cleaning solvent PD680 is toxic and
flammable. Wear protective goggles,
face mask, and gloves and use in a well
ventilated area. Avoid contact with skin,
eyes, and clothes and do not breath
vapors. Do not use near open flame or
excessive heat. The flash point for Type I
solvent is 100 degrees F (38 degrees C).
The flash point for Type II solvent is 140
degrees F (60 degrees C). If you become
dizzy while using cleaning solvent, get
fresh air immediately and get medical aid.
If contact with eyes is made, wash your
eyes with water and get medical aid
contacts are loose, tighten. If
contacts are dirty, clean using 600
grit abrasive paper (Item 8,
Appendix E) and dry cleaning
solvent (Item 11, Appendix E). Dry
Verify power coming from towing vehicle as
Set multimeter to 50 vdc range.
Refer to wiring diagram. Connect
multimeter red lead to towing vehicle
connector for inoperative lamp.
Connect black lead to ground.
Apply power as appropriate (turn on
light switch, apply brakes).
multimeter does not indicate
approximately 24 vdc, troubleshoot
towing vehicle (refer to appropriate
technical manual for towing vehicle).
If multimeter indicates approximately
24 vdc, continue with this