TM9-2330-372-14&P
(1) Clean intervehicular cable with clean rag.
(2) Inspect cable for cuts, breaks and loose connectors and cover for damage.
c. Installation. Replace in reverse order of procedure "a" above.
4-15. TESTING ELECTRICAL SYSTEM (Fig. 4-1).
a. Check for Grounds
(1) Disconnect all wiring connectors at the lights. Be sure identification markers are present on individual
wires before disconnecting; if not, tag wires.
NOTE
Check for continuity or grounds using the multimeter on a low ohms scale.
(2) Check for continuity between wiring harness connector pin and the chassis. If the circuit is open, repair
ground lead on wiring harness.
(3) Check for grounds between wiring harness connector pins, A, B, C, E, F, and J and pin D (ground). (Refer
to fig. 4-1 wiring diagram). There should be an open circuit between the connector pins. If there is continuity between
any connector pin as specified, that circuit is grounded and the wiring harness must be repaired or replaced.
(4) Remove all lamps from lights.
(5) Check for grounds from each light lead wire and the chassis (ground). There should be an open circuit
between each lead wire and the chassis. If there is continuity on any lead wire, the wire is grounded and must be
repaired or the light replaced.
b. Check Wiring Harness Continuity.
(1) Install all lamps in lights.
(2) Check for continuity between each light lead wire and chassis. If there is an open circuit, first check lamp.
If lamp is defective replace it. If there is still an open circuit, repair lead wire or replace light.
(3) Connect all wire connectors at lights.
(4) Check for continuity between wiring harness connector pins (ground).
Each circuit should indicate
continuity. If not, there is a broken wire and wiring must be repaired or replaced.
to the towing vehicle. To prevent damage to the multimeter, resistance measurements are made with the trailer
disconnected from the towing vehicle. Refer to fig. 4-1 for the trailer wiring diagram.
4-13
