Table 2-2. Unit Troubleshooting -continued
TEST OR INSPECTION
FLATBED CARGO TRAILER ELECTRICAL SYSTEM (Model WPES-I)
Flatbed cargo trailer electrical system contains 24 VDC which can cause severe burns. Be sure to
remove watches, bracelets, rings and other metal objects when working on brake electrical
Testing electrical system with power connected can cause damage to flatbed cargo trailer
electrical system. Take proper measures to ensure wires do not touch trailer chassis during
Before troubleshooting flatbed cargo trailer electrical system, ensure that towing vehicle's
battery is fully charged.
Ensure that there are no burned out lamps on trailer.
Turn lights on at towing vehicle.
1. TRAILER LIGHT INOPERABLE.
Step 1. Inspect connectors for damage and corrosion and check that power cable assembly is securely connected
to towing vehicle receptacle.
Plug in power cable assembly
Step 2. Unplug power cable assembly from towing vehicle and check that 24 VDC is available between pins D
(ground) and pins A, B, C, E, F and J at the towing vehicle.
a. If 24 VDC is present, go to step 3.
b. If 24 VDC is not available. Refer to towing vehicle maintenance manual.