# New To Me Tow Vehicle And Trailer Brake Issues



## Toolmaan (Jan 11, 2007)

Hey all,

Been awhile since I posted. Well I traded in my old truck and bought a 2001 F250 crew cab diesel (7.3L) to pull our 21RS. Just today I hooked it up to the camper and drove it and I am trying to get the trailer brakes working properly. This truck already had a brake controller in it, and when I hit the brake immediately the trailer brakes lock up, so I adjusted the brake controller, nothing I did made a difference. So I installed my old brake controller which I know was working fine last season, anyhow I got the same issue. Any ideas? Is this a truck or trailer issue? I am connecting the brake controller to the factory Ford plug for a brake controller. My previous Ford did fine. One thing I did notice is the brake switch is awful touchy, you barely touch the brake pedal and the brake lights are on. I looked and there is no adjustment on the brake switch. I would appreciate any ideas.

Thanks!


----------



## duggy (Mar 17, 2010)

It could be a brake controller issue, or a trailer issue. Does your brake controller have a digital readout, to show you what voltage is being applied? I wouldn't think the brakes should lock up unless the voltage is up at least to six volts or more, depending on the trailer. The brake lights coming on immediately, shouldn't be an issue. That should just apply a small initial voltage, which should increase as the inertia sensor detects braking force.

If the brakes are locking with a low voltage, that could be caused by contaminated brake linings. Any chance grease from the wheel bearings leaked into the brake drums? I'd pull a drum and see how things look.


----------



## #40Fan (Jul 7, 2011)

My guess would be that the braking wire on the trailer is crossed directly to your brake lights on your TV. Have someone stand beside the trailer while you move the manual slider on the brake controller. See if they can hear the brakes magnet being energized. Then hit the brake pedal and see if the noise is there. Might also have them watch the brake light bulbs on the trailer while moving the manual slider. See if they get brighter the more you move the slider.


----------



## CamperAndy (Aug 26, 2004)

I am going to go with incorrectly wired brake control harness. Either at the controller or at the pigtail connection at the back of the truck. Suspect the brake lights and the trailer brakes are crossed and you are getting full voltage to the brakes. Check the trailer lights are they dim? If they are then they are getting the controller output.


----------



## duggy (Mar 17, 2010)

I'm liking the mixed up wiring cause as well. I hadn't considered that possibility, but you never know what a previous owner might have changed at some time.


----------



## Toolmaan (Jan 11, 2007)

Thanks for the reply's. I looked at this issue deeper and figured it out. The gooseneck trailer plug was not original, I followed that and found the previous owner installed it with scotch locks, I hate those things. Anyhow on the trailer brake output wire where the scotch locked it in it had impregnanted the wire with corrosion. I disconnected the scotch lock, cut out the bad section and put it back to original, bypassing the gooseneck connector. Now it works great.


----------



## Bob Landry (Apr 18, 2011)

Are you trying to use both controllers?


----------



## CamperAndy (Aug 26, 2004)

Bob Landry said:


> Are you trying to use both controllers?


He fixed the problem.

He was using the two controllers one at a time to see if it was the controller or not. It was the wiring harness at the goose neck, corroded wires.


----------

