Trailer brake failure

Reply Subscribe

Thread Tools

Search this Thread

Dec 21, 2016 | 05:53 PM

StanleyZ

Thread Starter

Logistics Pro

Joined: Nov 2001

Posts: 3,788

Likes: 103

From: Georgia

Trailer brake failure

This is posted in the towing forum too but I thought I might get the attention of someone here that doesn't go to that forum. I gotta get this fixed as I leave for florida on the 31st. Ford built in brake controller. No brakes on trailer.

Squeezing the brake controller gives me battery voltage to the trailer brakes and the brakes work.

Pulling the stopper on the breakaway switch gives me battery voltage and the trailer brakes lock.

Pushing the brake pedal gives me nothing and no brakes on the trailer.

I've checked the fuse under the hood and both fuses in the cab. All are good.

I am open to suggestions. Thanks

Dec 21, 2016 | 06:00 PM

Sqidget

New User

Joined: Aug 2012

Posts: 21

Likes: 0

From: Richmond RI

Possibly a brake lamp switch, it uses one on the pedal with 4 wires.
that would be another place to check. Does the truck have working stop lights? I found fuse 31(5a) to be inline between the brake light switch and the trailer brake controller. (2012 schematic)

Dec 21, 2016 | 06:20 PM

Just Strokin

Post Fiend

Joined: Nov 2001

Posts: 6,748

Likes: 119

From: Tallassee, ALabama

What is the gain set on the trailer brake controller? Page 101

Did you read up on the Ford TBS in your owner's manual? Page 191

See page 90 about what you set the brake mode?

Electric or Electric Over Hydraulic

you can download a copy here

http://www.fordservicecontent.com/Fo...US_10_2013.pdf

Dec 21, 2016 | 06:36 PM

Just Strokin

Post Fiend

Joined: Nov 2001

Posts: 6,748

Likes: 119

From: Tallassee, ALabama

Did you check fuses in the BCM F31 and F35?

Did you check the fuse under the hood F22?

Quote:

Possibly a brake lamp switch, I don't know if it uses one or two on the pedal
that would be another place to check. Does the truck have working stop lights?

Now days they do not use the simple brake lamp switch but use input from the ABS module via the CAN network for info on the brake pressure being applied so the TBC can apply the brake accordingly.

Dec 21, 2016 | 07:03 PM

djousma

Logistics Pro

Joined: Mar 2005

Posts: 3,549

Likes: 2,510

From: West Michigan

So, to get a little history, and please forgive me, but you've towed with this truck/trailer combo before? I'm sure you are aware, that you get very little brake gain from the Ford TBC at a standstill?

Dec 21, 2016 | 07:49 PM

StanleyZ

Thread Starter

Logistics Pro

Joined: Nov 2001

Posts: 3,788

Likes: 103

From: Georgia

Quote:

Originally Posted by djousma

You know I hate it when I feel stupid. Thank you. Yes I knew that and I've even encountered it before. But I guess there is something about getting older that causes brain farts of an epic size. Of course that is the answer. Nothing happens below about 12 MPH I think. Thanks to all who answered. Especially those who read the thread before answering.

Dec 21, 2016 | 08:27 PM

djousma

Logistics Pro

Joined: Mar 2005

Posts: 3,549

Likes: 2,510

From: West Michigan

Take her out for a spin just to calm your nerves. If thats all it turns out to be, well, we all have brain farts occasionally. Sounds like you are in store for a nice trip to Flo-rida. I'm jealous. Wading through 16" of snow here in Western Michigan, although we do have a slight warming trend on the way.