UNIT TROUBLESHOOTING - CONTINUED
TEST OR INSPECTION
2. ALL LAMPS FAIL TO LIGHT, ARE DIM, OR FLICKER
Step 1. Check fuses and circuit breakers in towing vehicle.
Replace any bad fuses or reset any tripped circuit breakers (refer to TM
applicable to towing vehicle). If fuses and circuit breakers are good, go to step
Step 2. Check for power at the towing vehicle receptacle.
Connect black lead of multimeter to pin D of towing vehicle receptacle. Use red
lead to probe all other pins in receptacle. If multimeter shows that power is
present at the receptacle with the light switches on, go to step 3. If no power is
available at the towing vehicle receptacle, repair towing vehicle electrical system
(refer to applicable TM).
Step 3. Check for corroded or damaged cable connectors, pins, or cables.
Check the condition of the receptacles, pins, and connectors on the
Both intervehicular cable (front harness) connectors.
All junction box receptacles.
Both interdolly cable connectors.
Check the condition of all electrical cables.
Repair any bad connectors, pins, or receptacles replace defective cables.
If no bad connectors, pins, or receptacles are found, go to step 4.
See page 4-60 for proper pin connector to wire identification.
Step 4. Check ground wire 90 for continuity between front intervehicular cable (front
harness) connector plug and rear dolly frame (page 4-60).
Repair break in ground wire 90 in the intervehicular cable (front harness),
junction box, interdolly cable or rear harness as applicable.