Troubleshooting Curt Discovery Brake Controller Issues on Ram 1500

Question:

i have recently aquired a new trailer that has tandem axles with brakes. there were electrical issues so i rewired the whole trailer and replaced bearings brake assemblies, all lights and brake away kit. now that i am towing the trailer, i am having issues with my new curt discovery brake controller. when i let off the gas it will engage the brakes on and off and when driving the controller will be randomly engaging brakes. the screen flashes and just keeps turning brakes on and off until i hit the brakes or gas. it just kept flickering so i had to turn the gain all the way down to 0 and the whole rode home it said 0.0 even when i wasnt hitting the brakes. any ideas? any help is appreciated

asked by: Brendan

Expert Reply:

The Curt Discovery Brake Controller # C84VV is a time-delay type that is intended to send out a pre-determined amount of braking power after you have applied the vehicle brakes. The other type that is often preferred is the proportional type that will actually sense the amount of braking force in the tow vehicle and send a proportional amount of braking power to the trailer, without a time delay.

Based on the symptoms you described I think the issue could be with the wiring on the trailer. Something as simple and "harmless" as a stray strand of wire could intermittently bridge one of the other wiring circuits over to the brake circuit. This would explain the random braking you experienced on your drive home. Corrosion could do the same thing, but since you have re-wired the entire trailer, I am thinking you do not have any issues with internal corrosion inside the trailer's male plug.

Corrosion can develop inside a connector and be hard to see. If you re-used your 7-way male plug on the trailer side then this part could be the issue. If you wired the trailer with a junction box you can also check that for any loose strands of wire that could be intermittently bridging the brake circuit with another.

If you have another trailer you can use for testing this too will help narrow down the source of the issue. If the controller works correctly with another trailer, then check your trailer wiring. If it has the same issue with another trailer, then check the vehicle side connector for corrosion, trapped dirt, etc. Likewise, if you have access to another tow vehicle/brake controller you can test the trailer with that vehicle to see if the issue persists.

If you have a circuit tester like # PTW2993, shown in the linked video, you can test the vehicle socket (with the trailer not connected) to see if the correct braking signals are reaching the contact in your 7-way socket. Please refer to the linked image of a 7-way socket. Set the unit to maximum power and apply the manual lever. The brake signal should be carried on the pin at the 5-o-clock position. If no signal is present, then the controller itself and/or the vehicle wiring are suspect.

expert reply by: Adam R