Hi, new member here. 2011 F250 SD. OEM fifth wheel towing package. Leaving campground I discover no trailer brakes using brake pedal.

If I adjust the controller so the gain is showing, and while it's showing I touch the brake pedal, I briefly get "output" but then it goes away, which is not normal. In layman's terms I assume the pedal is talking to the controller and the controller is sending the voltage to the brakes. Since the truck recognizes "trailer connected" and I can apply the brakes manually using controller that seems to eliminate the brakes, trailer wiring, harness and controller. Leaving the truck. Since I get a brief "output" that seems to eliminate fuses and I've checked every fuse that seems relevant.

Is there some sort of rheostat thingy that sends variable brake pedal output to the controller? Where is it located? The only electrical connections I can find near the pedal is the stoplight switch (stoplights work on trailer) and what I'm guessing is a brake fluid low level light connection (located on side of brake reservoir.

Help! (thx)

 

May not do anything, but I’d check the trailer plugs/connections first - make sure they’re clean and tight and pins are all straight and connecting in the plugs. Just to rule that out first

 

The folks with answers to this kind of thing don't usually frequent the "New Member Introductions" forum. You might want to post in "1999 to 2016 Super Duty" and/or "Fifth Wheel & Gooseneck RV Towing" forum to get some answers flowing.

Welcome aboard!

 

Moved to appropriate forum

 

Thanks and sorry for the late reply. It turns out you were exactly right. As I worked from the trailer forward I determined the brakes were working, and could be activated by the controller. This seemed to make the problem a truck issue. Almost. Even though I had already, a week before, cleaned both the male and female parts of the plug with contact cleaner, running out of ideas I followed someone else's suggestion to spray WD40 in the plug. As I inserted and removed the plug several times I noted that it didn't really firmly go in to place. I had a look at the female end and the spades had all pushed apart a little so they weren't making good contact with the male spades. I adjusted all 7 and I had brakes!

I'm guessing the reason the brakes seemed to work when manually activating the controller, is that when I did I was applying full braking (highest voltage). This higher voltage was able to bridge a high resistance gap and apply the brakes. At anything less than 100%, such as when pushing the pedal, I got no brakes. Just a theory.

(Note to moderator - thank you for moving this, I know better as I'm active on another forum. I was in a hurry and just slammed out a post. This should probably be in the fifth wheel section as suggested)