Trailer Brake Controller barely applies brakes
 

I have a 2017 f250 diesel crew with intigrated brake controller. I have towed 2 new trailers with it. Both times even with the gain set all the way up and the surge setting set To high the brakes are only slightly apply when sliding the actuator lever fully over during a brake check. In fact it seems like no matter what the gain is set on the brakes engage the same and that is barely. I should be able to get a new trailer to lock up I would hope. One trailer was 8000 one was 9500. I read somewheee it may need to be reprogrammed or flashed at the dealer. Any help? Thanks so much!’

Trailer brakes are an assisting device. They help to slow down the trailer and help to keep everything under control.

The actual test of the controller is if you move the slide over while the truck rolls at idle. Does the trailer stop the truck from rolling at idle? If it does you are good. Set the gain just above the point it will stop the truck at idle.

Lock-up on the trailer when the trucks tires are still rolling can cause serious problems especially on slick roads. I ended up sideways coming off the mountains in Wyoming in a snow storm once because the trailer brakes locked up and it started to come around. 10,000 lbs of tools in a 17'.

My new trailer doesn't stop the truck when I manually move the brake controller over.

There is brake dust all over my front rims.

When I pull my break away cable, the trailer batteries don't lock up the brakes and my last three trailers did. Shouldn't the new trailer brakes lockup.

When you pull the break away cable, yes. But you should NEVER leave that cable pulled like a parking brake. It will fry the wires going to the wheels. If ypu left this cable pulled you should check the wiring to see if it burned itself in half.

As for the original poster, Ford's TBC has always worked this way. You have to be going forward about 15 MPH for the TBC to work correctly. The controller works in conjunction with the anti-lock braking system of the truck too.

Thanks

I'm going to pick my Trailer up today. I don't like taking a knife to a gun fight.

I'm also going to look and bring the government regulations.

I never left the wire pulled. Wire is rated for over 10 amps, but I will heed your warning. Each brake coil is drawing 3 amps

If the brake won't lock up with the emergency battery pulled, then I would look at the brakes on the trailer.

Though I don't use a new truck with a built in controller I dealt with weak brakes for a few years. No matter what I did, they were weak. Barely hold the truck from rolling at 100% gain. Not good. I inspected the pads/magnets and they looked fine. I even rewired the trailer brake wire and soldered all joints(instead of factory scotch loks). Nothing really worked.

I finally ordered 6 new loaded backing plates(triaxle), turned the drums and WOW, instant brakes. I now run my gain at about 30% and it pulls down nicely. You can feel it just tug at the truck.

Before you get to carried away check and make sure your controller is set for electric brakes and not electric over hydraulic unless the trailers you have pulled have disk brakes then you want the hydraulic option. Electic are current based with power coming from the truck, hydraulic are voltage based with operating power coming from the trailer.

Denny

Check and see what size brakes are on the trailer, easy way to save money is to undersize them.

Denny

I forgot one problem you COULD be having. Pull wheel and check to see if someone overloaded while servicing the wheel bearings and got grease on the drums and linings..... if they did it cannot be cleaned off. Prob would need new linings and drums.

Thanks for all the help.

I thought the right side brakes had no wires to them. but after thought about it, I couldn't have 12 plus amps when pulling the breake away switch.

Sadly I already sent Emails out to the dealer. I always tell people to think before you press send, good advice.

Thanks again

Well
I ran around all day trying to get some answers, but have more questions.

This is what I'm sure of without hooking up the trailer. When I pull the breakaway cable, 13 amps is measured on the switch wire and 3.3 amps at every brake coil. I really wanted to hook and try moving the trailer again but didn't have the time. But I did yesterday and it moved with the cable pulled.

Now for the truck. Not what I expected. Checked it multiple times.
Connected a clamp on amp meter to the blue brake wire from the TBC at the back of the 7 pin connector.
When I manually move the TBC slide switch all the way over, the TBC output would put out the same amount of what the gain is set at.

So
The dealer set my gain at 8 and the output was almost 10 amps. When I set the gain to 10, the output was just over 12.

I always thought that the switch took the TBE and truck's computer out of the picture.
But mine is not, so do I have a bad TBC or not???

So
When I get a chance, I'm thinking move the trailer with the breakaway cable pulled. The tires should be locked up,if not locked up the trailer brakes need adjusting (dealer says their self adjust),
I'm going to use a Bluetooth fluke meter to measure current to the trailer's brakes.

If anyone thinks of anything else to try, it would be great.

Other than the greasy drums and linings. not me !

Has anyone ajusted the brakes, drum electric brakes have a limited arm swing to apply the brakes so the shoes have to be close to the drum, actually slightly coming in contact with it after adjustment. Even if you have self adjusters you have to start out with well adjusted brakes for them to work.

Denny

Thanks for the replies.

I was thinking the same way.

Dexter says that new brakes have to be manually adjusted after 200 miles.

I wish I could get it through the kid at the dealership.

For heath reason's I have to wait till my wife leaves so I can work on it.

thanks for the info. I was always told to get the truck and trailer vehicle up to 15 mph or so let it coast and apply maximum trailer braking without using the truck brakes. Adjust it so that it is below the point it locks up at maximum application.

As as far as stopping at idol I am not sure what you mean. At max output coasting a bit at idol the trailer brakes will slow me to a stop but just barely and takes forever. And it doesn’t seem like a difference regardless of where the gain is set.

I know to adjust is below the point of locking up but as it is now I fear the opposite will occur. The trailer is going to push the truck and going downhill around ancurce if I have to brake hard I will be in trouble. Hope that makes sense