I have a 05 f350, 6.0 4x4, having issues with the factory brake controller. at 15mph gain set to 10 and I use the manual slide the trailer brakes barely slow down the truck, what should the output voltage be with the gain set to 10 and I move the slide all the way to max? I woul think this would lock up my trailer brakes (11K 5th wheel)

 

I would caution against blaming the controller as a first step. There are a multitude of things that can affect trailer brake performance. A weak ground, poor connections, and brake adjustment are some of the obvious ones. Controllers of any make are last on my list of things to check when it comes to trailer brake performance.

Steve

 

I agree, This is a brand new 5th wheel, just picked it up this weekend, I plan on adjusting the brakes tonight to be sure. I have a buddy with the same 05 f350 Im going to test on my trailer later this week. I did hook up a friends truck and pushed the manual slide and you can really hear the magnets hum, when you do the same thing with my truck you can barely hear them.

 

Since you already know your trailer brakes are good, it does not seem necessary to check it again. Focus on the connections on your truck or hook your truck to your buddy's trailer and see how it does. I think you will find this is a connection issue as those are far and away the most common problem. The Ford seven pin plug is extremely prone to water penetration at the rear of the plug and it can appear to be making good connection with the ground pin on the bottom of the plug almost rusted off. Good connections are essential to brake operation.

Steve

 

I guess the best thing to do is try my truck on someones camper and see if its the same thing, I just had the 7 pin connector apart to install a extension 7 pin in the bed, the connector was spotless on the inside, no corrosion, dust/dirt or signs of water penetration.

I just figured if I new what the controllers output voltage was when set to a gain of 10, and manual slide completely engaged I could check it at the junction box on the king pin box.

 

It will be about battery voltage less about a volt due to resistance in the circuit. You should see well over 12 volts.

Steve

 

The Ford TBC is very smart. It knows you don't have to lock up the brakes going that slow.

 

That maybe true, but if you follow the calibration procedures in the ford manual it tells you that it will unless you are pulling a really heavy load. Regardless, with the gain set to 10, and i push the manual control all the way it should bring the truck close to a stop, and it currently doesnt come close

 

Is this a new to you truck? Reason I ask is that the early 2005's were programmed just how you describe, they don't activate fully unless you're going over 10-15mph. That was fixed mid year so if yours is an early build it could have that problem. Afraid the only real fix is replacing the controller w/ a newer one or deal w/ the operation as it is. It should work fine at greater speed. Here's a couple links: https://www.ford-trucks.com/forums/9...-question.html and https://www.ford-trucks.com/forums/8...operation.html

 

I could be mistaken, but as I understand the early 05s, operating the controller manually should lock the brakes regardless of speed, which is what the OP is doing. Right?

Steve

 

I bought the truck new in May 2005, it was built in Mar 05, I towed a 9klbs 5th wheel, it worked ok, sold the 5th wheel a couple years ago and just bought a new one which weights more, 11Klbs. when I went to calibrate the controller to the trailer thats when I noticed the lack of braking.

 

Got it, but it doesn't lock up on manual activation either, right? If it locks on manual, but you can not calibrate it when moving and using the brakes, it is the controller, pure and simple. If you can not lock it down on manual, that is a different issue.

Steve

 

Thanks for those links, I bet my truck was built before March 23 05 and thusly I only get up to 3 volts from the controller to the brakes, if it was built after the 23 Id be getting 10 volts, how do I determine the exact build date

 

No it will not lock up on Manual, they wont lock up no matter how you try it,

Thats what I thought should happen, the brakes should lock up when gain is set to 10 and I use the manual slide switch, then back the gain down till the trailer brakes stop locking up,

 

So the next easy thing to do is test the trailer by pulling the break-away pin with the trailer hitched, but the seven pin left unplugged. doing this the trailer should be stuck fast. If it is not, the problem is with the trailer (not likely).

If it is, reinsert the break-away pin and verify the voltage at the brake pin on your seven pin while operating the controller manually. What did you get? If you have have more than 12 volts, the trailer should do the same think using the controller manually that it does with the break-away pin pulled. Do you have 12 or more volts? We're not done yet, but I don't want go too fast and you may have already done these steps.

Steve