RDozier

I've got a 2011 F150 XLT without the integrated trailer brake controller; I have an aftermarket controller. I've had the truck since new in July 2011 and have had no towing issues until this year; usually towing an 24 foot , tandem axle, enclosed trailer with electric brakes.

Earlier this spring when towing a friends trailer, a short in his trailer caused the 30amp trailer brake fuse to blow. I replaced the fuse and found when I went to tow my enclosed trailer, the electric brakes will not activate through the brake pedal. On the trailer, all running lights work, turn signals work, brake lights activate with the brake pedal and the trailer brakes can be activated with the manual slider.

I took the trailer to be inspected by a trailer company and they found that each time 12v was applied the trailer brakes activated so the trailer has been ruled out as the issue.

In an effort to determine if my brake controller was bad, I swapped out the controller from my motorhome and also purchased a new brake controller however the same issue continues so I believe the brake controllers have been ruled out. I also checked and the controllers are getting 12v power but the blue wire has nothing when the brake pedal is depressed.

I have checked a 10amp fuse in the kick panel from the manual (maybe #37 but don't remember definitive right now) and found it to be intact. Is it possible that a relay has gone bad due to the short which caused the 30amp fuse to blow and if so, which relay would that be?

Thanks for the time!

smokeywren

Hi, RDozier, and welcome to F150Forum.

If you checked #37 10-amp fuse under the dash as well as #17 30-amp cartridge fuse in the power distribution box under the hood, then as far as I know that's all the fuses/relays required for your trailer brake system to work.

Next step is to be certain you have a "hot" trailer brake controller wire in the 7-pin trailer plug at the back of the truck. Use a 12-volt test light and a helper to be sure the trailer brake controller pin (blue wire) is hot when the brake pedal is depressed, and is not hot when the brakes are not applied.

Here's a good resource to help you figure out which of the 7 pins in your trailer wiring plug is the brake controller pin.
http://www.etrailer.com/faq-wiring.aspx

murf

it's the number 9 relay if I'm remembering correct. I have mine jumped for lights in the back, you can make a quick jump wire to see if it's the relay.

here's a pic


This is from a thread on how to put LED bedligts in your truck.

https://www.f150forum.com/f38/led-bedlights-143928/

tomb1269

I am not sure of the exact wiring for your 2011 but from having wired my own cars with brake controlers it sounds as if you are not getting feed from the brake light circiut to the brake controller. Remember, the brake lights are run on their own circuit. If you install a brake controller in a car not pre-wired for it you have to use a pigging backjumper (the blue things that have the metal slide that taps the wire thru the sheild) to the brake switch wire coming of the brake pedal. And it is is own circuit and has nothing to do with lights to the trailer. Basically a 7 pin coupler is wired up as if you had a 4 pin lights only plug at the back and then added a constant 12volt hot and the brake activation signal wire (i.e. blue wire). So find where you get you brake activation signal from, most likely a relay in the pwoer panel as MURF stated.

murf

Sorry. The 9 relay of for power to trailers. Don't know what I was thinking. That relay has nothing to do with the blue wire for trailer braking.

tmajor

Hi All,
I've got a 2012 F150, which doesn't have the factory tow package. I asked the dealer to install a hitch and 7 pin plug. That has been wired into the factory 4 pin plug truck wiring, but only gives me lights, signals and stop lights.

I re-installed my old Tekonsha, Voyager TBC (hard wire version), which doesn't work. The one problem, which I have found, is that the electric brake wire (Blue) doesn't go through to the 7 pin plug. It doesn't even appear to make it to the intermediate plug by the spare tire.

I know the Orange charging wire dead-ends (doesn't go to the back) at a plug on the left front fender. The factory TBC connector, by the steering column, looks complete (includes the Blue wire).

Does anybody have any idea where I might pick up the Blue wire? Under the dash? Under the hood?

Thanks for any help.
Tom

tmajor

I believe, I've found some of my answers. After reading an eTrailer article, I looked further into the connector on the left inner fender, where I had found the Orange wire. The Blue wire was also present. The Orange (charging) wire is the 1st in the center row of pins (end facing the engine) and the Blue (Trailer Brake Signal) was the 3rd in the same center row. Neither of these wires went beyond the mating connector. So, I'll have to splice into these with T-connectors and run the wires back to the 7 pin plug.

Edit: Actually, I cut the wires and used butt connectors.

CrazyFire

I have a 2010 F150 XLT 4X4 with a similar problem as the first post. I however have the factory installed TBC and everything seems to work fine and is set up. Here is my dilemma....With my camping trailer attached (25 ft prowler), all lights, charging, etc. work when tested. The brake lights on the trailer worked then as well. While driving, I seemed to have no electric trailer brakes when the brake pedal is applied (Gain was set at 7). I do have trailer braking when the slide on the TBC is used. I maxed the gain out at 10 and nothing. The trailer has been checked out and is fine. All fuses seem to be fine as well. When I attach my 7 pin tester all lights work as they should except for the brake pedal (very week signal when present and intermittent). I used my 12V test light and had no light at all when the brakes were applied. I went back to the connector at the spare tire and again no light showing a signal. I have now moved up to the dash and this is where I get lost. I'm at a loss as I find it hard to reason with the fact that it is the same line (blue) from the controller. I'm no mechanic but I think it is where the pedal and the controller merge. But where exactly is that. I've looked at the plug on the drivers wheel well, I'm looking currently at the plug by the drivers foot well/kick plate (forgive my terminology). Any other suggestions or what have I missed? I'm sure I will be starting from scratch.

Any help is appreciated.

Steve

tmajor

Steve, I'm not sure you would normally have much of anything on the Blue Brake wire, unless you are applying the brakes, when moving. ... maybe , if the gain is turned up. The Blue wire is a straight shot to the 7 pin plug, with some connectors in between,

Separate the connector between the TBC and truck wiring, ground the Blue truck wire, then go back to the 7 pin connector and see, if the Blue wire is grounded. ... provided you have an ohm meter or other tester. Remove the ground from the truck TBC connecter and see, if the ground at the 7 pin plug goes away.

tmajor

I posed my problem to eTrailer and they posted an answer for me. Also, information/instructions for the 20270 and 20272 adapter cables.

I got the Blue and Orange wire run, but it still doesn't work. After looking at the difference between the two TBC cables, I can see why. Hopefully, I can disassemble the connector and make the changes.