Troubleshooting Lost Brake Circuit Connection with HydraStar EOH Adapter Module HBA-CAM  

Question:

Expert Reply:

The most common cause for a connection problem with the HydraStar Electric Over Hydraulic Actuator Adapter Module # HBA-CAM is a corrosion issue in either the vehicle 7-way socket or the trailer's 7-way plug. Even slight corrosion, which can appear as a whitish or greenish film on the contact surfaces, can block the brake circuit's signal and cause the brake controller to not see the trailer and the # HBA-CAM in the circuit. This can often be corrected with a cleaning using an electrical contact cleaner like Caig De-Oxit.

First, I suggest you apply a circuit tester like # PTW2992 to the truck's 7-way socket to verify that the brake controller output signal is present on the contact at the 5:00 position. Ground the tester to the ground contact at the 7:00 position and apply the tester's probe to the brake circuit contact at 5:00. You can refer to the linked photo to see these two contacts. Have a helper press the manual override on the controller while you test.

If you detect the signal on the truck's socket, then the issue is likely to be either on the trailer plug or elsewhere in its brake circuit wiring. If there is no brake signal on the truck side, then you will need to trace the brake circuit wiring forward looking for worn insulation or a short on that wire. Spots where the brake circuit wire may touch the frame are likely to be the trouble spot.

Repeat your check on the trailer side plug and clean the contacts and again trace the wiring looking for any places where the wiring may be rubbing the trailer frame.

expert reply by: Adam R

0

click to enlarge