What the $^% is wrong with my trailer brakes?

[Darel]

OK, I have a '97 with the factory tow brake setup. The only way the red light would come on would be if you stepped on the pedal and fingered the controller at the same time.

I figured the problem was in the controller, so I bought a Tekonsha Prodigy. It is wired correctly, all I did was cut the factory plug off the old controller and splice the harness for the Prodigy on it. Yes, I double and triple (then later cut off all my electrical tape and quadruple) checked the wiring. I get the red light on the display indicating the controller has a good 12V circuit. Supposedly, when I plug a trailer into the socket on the hitch, regardless of motion, I should get a "c" on the display. No "c". If I finger the controller I get "nc", which means no connection. When I finger the controller and step on the pedal at the same time, I get a blank display with just the little red light for 12V power. Basically, the controller isn't recognizing that I have a trailer back there. A test light on the plug confirms all this, I only get current when i finger and step simultaneously.

I have tried this on 4 different trailers, two less than a year old. Same results every time. I know the prongs in the 6-round plugs are matched up because like I said, the brakes used to work when I fingered the controller and stepped on the brake at the same time. What is the problem? The lady at Tekonsha Customer Service (who was really *****y, by the way), basically confirmed that the controller is working properly and is hooked up properly. She wasn't any more help than that. The controller has displays for short circuits, overloads, bad grounds, and a couple of other common problems and it indicates none.

Please help! This problem has been driving me nuts for months!

 

[Shooter]

You did not say if the trailer brakes ever worked with just the pedal. Another item is the factory pigtail color code do not match the brake controler color codes but i'm shure you already knew that.

 

[Darel]

The trailer brakes did work for a while, then they stopped working properly and started the whole finger-pedal deal.

Also, I know the colors don't match, I used the wiring guide provided with the Prodigy to wire it up. The tech support lady confirmed my wiring was correct.

Thanks!

 

[rob10858]

well, i'll show my ignorance, but share my experiences. we've had trucks where the brake controller only worked manually, did'nt work manually, but only when the truck brakes were applied, and combinations of all of the above. in laymans terms there is a wire in all brake controllers that either receives or sends a message to the brake controller from the foot brake on your truck. start there. it may be blue, black, green, who knows? some of our ford trucks have straight black wiring that really make it difficult to distinguish what the problem is. what you describe really sounds to me like two wires that are crossed , even though the diagrams show them as correct. if the same problem presents itself with different trailers and the same truck, that narrows it down to the truck, period. a good wiring man, whether dealer or shadetree, can solve this for you for about $50 bucks. spend the money and save yourself the hassle.

 

[Paul Somers]

Does your cruise control work? There is a switch on brake pedal that dis engages cruise when pedal is depressed. Brake control uses this same switch. Maybe out of adjustment or defective. Just a thought.

 

[Darel]

Cruise works fine, just used it 2 days ago.

 

[Darel]

UPDATE:

Replaced the 40A fuse, relay, and socket in the rear of the truck. It was pretty corroded, but now it's brand new. Again, I know I got the wiring right because all of the lights work properly, and hell, there's only one other wire. I also replaced my hitch, because on the driver's side it was cracked almost all the way through! The PO must have WAY overloaded it because my towing hasn't even come close to rated capacity. I'll post some pictures later. The trailer grounds through the socket. I did clean up all the ground connetions. We also blew out all the wiring harness plug-ins while we were in there. A bud and I found another socket spliced into the factory harness up in the bed, for plugging in a slide-in or gooseneck. I've got a plastic bedliner so I never saw it before. Anyway, we removed the second socket and lo and behold, I get a proper signal to the brakes (as evidenced by a test light that gets dimmer and stronger as you finger the controller OR step on the brakes), however the Prodigy controller still will not recognize the connection. I still get "nc", and have yet to have gotten a "c". If nothing else the brakes should work now, but I spent a lot more money for that controller than I had to, so I'd like it to work properly. Any more ideas?

Thanks for your help so far!