Help required. I have just purchased a Camper trailer and am having some issues with the electric Brakes. I am working with the trailer manufacturer to resolve this issue and yes we are getting there. I think we are just about at the point of replacing the Brake assemblys unless some of you guys can provide a
beacon of light. I have documented the symptoms and trouble shooting done below. Please feel free to comment.
Cheers Cruisin
Fault finding done and fault symptoms of 12” Dexter Electric Brakes.
Symptoms
The symptoms below have been found using my Tekonsha Prodigy Brake controller in my own vehicle and also using Wayne’s standard ATS brake controller in his own vehicle
1. Brakes weak and inconsistent, will not lock the rear wheels up. With earlier testing we could sometimes get the wheels to lock up but was not consistent. Recent testing with two separate vehicles and controllers saw that neither vehicle could get any wheel to lock up with the controllers set to maximum..
This applys to both brake assemblys as we cannot lock up either side wheels.
2. Brakes are shuddering/surging when braking slightly harder than normal and in the last 50 metres prior to a complete stop.
As these symptoms where found using two separate vehicles and controllers we can assertain that the problem lies in the Electric Brake assembly or the wiring on the trailer. Wayne has not experienced this shuddering, or not being able to lockup the trailer wheels using his vehicle on any other of his trailers.
Trouble shooting performed.
1. Apon inspection of the trailer, 7 Pin plug, Wayne realised that his builders had used 3mm cable for the brake wires. I have since rewired the Brakes using 6mm Auto Cable. This has made no difference to the performance or symptoms of the brakes.
The following measurements were made using the Tekonsha Prodigy Controller with the output set to Maximum and applying the brakes using the manual lever on the controller.
Voltage measurements using 3mm cable wired to the brakes (Original Wiring)
At 7 pin plug, Pin 3 & 5 13.04 V
At RHS Brake Assembly 12.45 V
At LHS Brake Assembly 12.32 V
No current measurement taken
Voltage measurements using 6mm cable wired to the brakes (Current Wiring)
At 7 pin plug, Pin 3 & 5 13.45V
At RHS Brake Assembly 12.9 V
At LHS Brake Assembly 12.88 V
Current draw of Both Brakes measured at
Pin 5 of the trailer 7 Pin plug. 6.21 A
Current draw of brakes with the 6mm Cable was 6.21 Amps, this is normal for a two brake system.
2. Wayne has removed the Brake hubs and adjusted the brakes to 6 turns out as recommended by his supplier. This also made no difference to the performance of the brakes.
Wayne also inspected both brake assembly and could see no uneven wear on the brakes indicating shuddering or incorrect operation.
Conclusion.
As we are seeing the correct voltage and current being applied to the brakes we cannot have an Earthing issue. With this much voltage on the brakes a correctly functioning brake assembly should easily be able to lock up the trailer wheels.
With the shuddering...If the Brake hubs were slightly out of round, this may cause some shuddering but should not stop the wheels from being able to be locked up.
All of this testing has been done with an unladen trailer weighing approximately 800kg.
One must therefore assume that we have a dud batch of Brake assemblys on our hands or a Pair of Magnets that are not operating as they should.