Intermittent Trailer Braking With Prodigy P2 On Caravan

Question:

The P2 system will operate regularly sometimes for perhaps 10 minutes then just cease working, display is still lit, has a letter c on it, but no breaking to the caravan. On Tuesday after rechecking wiring and re cleaning plugs the system worked for the whole test of about 15 minutes. Later that day got back in the car to move the van back to storage & brakes not working. Letter c still showing on display with power obviously but no response in the braking system. Any thoughts would be greatly appreciated many thanks

asked by: David

Expert Reply:

I can help you troubleshoot the issues you are having with the Tekonsha Prodigy P2 part # 90885.

On the Prodigy P2 Brake Controller # 90885 the displayed message, C, indicates that the unit has 12V power, has its boost feature engaged and that it detects a connected trailer. It is possible for the Prodigy to display this code even if you are having issues with the braking.

You did say you had better luck when you cleaned the plugs and checked the wiring. It is a good idea to make sure the pins on the 7-way vehicle plug and trailer plug. especially the brake output pin is free of corrosion or dirt.

If your pins are free of corrosion or dirt, it sounds like you have a short on the blue brake wire somewhere between the brake controller and the trailer brakes. Check the brake output pin on the 7-way vehicle connector with a circuit tester like part # PTW2993 while someone applies the manual override on the brake controller. If the circuit tester is fully illuminated, then you are getting full voltage to the pin on the vehicle side and the issue is on the trailer's side wiring. You want to check the blue wire on the trailer side for frayed or damaged wiring. You also want to check the grounds on the braking assemblies to make sure they are properly grounded to a clean bare metal surface on the trailer's frame.

If the circuit tester is not showing full power (dimly lit) at the brake output pin or no power at all, then the brake output wire between the brake controller and the vehicle's 7-way is the issue. If the brake controller is hardwired in (without a factory brake controller port) then you want to make sure all of your connections are properly connected, especially at the stop light switch. Check the ground the brake controller as well. It sounds like the 12V power is working properly on your brake controller since you have the display.

If all of your connections are properly connected, you want to test the blue wire from the back of the Prodigy. You can cut the blue wire 6 inches back from the brake controller to test for voltage. If you do not have proper voltage there, the brake controller needs to be replaced.