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Discussion Starter #1
I've running the oem built in Trailer Brake Controller (TBC) in my 2005 F250 with the 6.0 in it. 95% of the time, the TBC works great. It's nice and smooth with applying the brakes in my camper, boat, or utility trailers...and seems to have plenty of power.

BUT......any time I'm going slower that around 10mph, even though it's showing that it's putting out power on the display, it doesn't put any power to the trailer brakes. Even if I manually squeeze the actuator lever all the way down, ZERO stopping power.

I read someone one one of the forums that this is normal for that year TBC's.....you need to get up to 10mph before it starts applying braking power. Is that true? If so, why in the hell would Ford design it like that? It's caught me off guard a few times going down steep hills at a slow speed, or rolling up to a stop light....you pretty down on the brakes, and the trailer just tried to push the truck. Talk about dangerous!!

Is there any fix for this besides putting in an aftermarket TBC? Any info on this would be great! I can't be the only one who hates this "feature" on the OEM TBC's.

Thanks for the info!
 

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This is all I can find so far ..............

At very low speeds, including at rest, the Ford controller sends a proportionally smaller amount of output voltage (though not zero) to the trailer brakes to provide smoother stops. This low-speed adjustment is the reason manual activation of the Ford TBC cannot be used to verify the operation of the trailer brakes.

You might try the tests below:

Drive the towing vehicle and trailer at 15 mph (24 km), at the maximum gain setting (10.0 for Ford TBC) and manually activate the Ford TBC. If a large deceleration is felt (a "jerk") the trailer brakes are operating correctly.

If it is absolutely necessary to have a test initiated with the system at rest, set the controller gain to maximum (10.0 for the Ford TBC) and manually activate the controller with vehicle in PARK. Have an 'inspector" kneel beside the trailer axles and listen for the "hum" an electric trailer brake will produce when current is being sent. If the hum is present, the trailer brakes are operating and the Ford TBC is sending its speed-adjusted output.

Another suggestion for a test with the system at rest would be to disconnect the trailer wiring from vehicle. Using a wire with clip on one end and a needle on the other (rated for 30A), attach the clip end of the wire to the battery charge terminal in the vehicle connector attached to the bumper. This pin corresponds to the black wire, and when looking at the vehicle connector, is in essentially the "1 o'clock" position (or the first pin when traveling clockwise from the 12 o'clock position – refer to figure below). Then rest the trailer hookup connector so it won't move around easily and insert the needle end of the wire into the brake output pin on the trailer connector. This pin corresponds to the blue wire, and when looking at the trailer connector is in essentially the "7 o'clock" position (or, the 4th pin when traveling clockwise from the 12 o'clock position). This will essentially send 12V to the trailer to charge the trailer brakes, but will not cause any potential damage to the emergency breakaway system.
 

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Also (FWIW):

The sliding lever on the TBC should be used only for manual activation of trailer brakes when adjusting the gain.

Misuse, such as application during trailer sway, could cause instability of trailer and/or tow vehicle.
 

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Discussion Starter #4
Yep....that's pretty much the same info I found.

I'm just wondering WHY Ford would set it up like that? If your hooked up to a 10,000lb trailer and you try slowing down on a hill and you are only going 10mph...you have NO TRAILER BRAKES!

Do the guys that tow heavy loads just deal with it, or replace the oem TBC?
 

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What I posted doesn't exactly say "zero".

It said ......

At very low speeds, including at rest, the Ford controller sends a proportionally smaller amount of output voltage (though not zero) to the trailer brakes to provide smoother stops. This low-speed adjustment is the reason manual activation of the Ford TBC cannot be used to verify the operation of the trailer brakes.

I have never had a problem, but I don't tow heavy loads and have very few hills in the area.

The tow/haul feature in the transmission would be a help if you haven't already considered that.
 

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Discussion Starter #6
If it's applying power....it's not enough to do anything...maybe a volt or two. Yes, I use tow/haul mode.....but it does nothing when you are rolling down a steep hill at 5-10 mph. What's the point of having brakes on your trailer if they don't work below 15mph?? Even in an emergency, if you squeeze the lever to manually activate the brakes.....under 10-15mph....you get nothing (ok....maybe 1 volt). Horrible design for a TBC.
 

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If you are hooked to a 10k trailer doing under 10mph downhill you have some serious edge case issues happening.

The cool part is that if you dont like the way this 20 year old TBC technology works you can install any one you would like.
 

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Discussion Starter #8
Edge case issues?

I'm talking about pulling down a steep driveway, or boat ramp, or some other situation where you might want to have the help of some trailer brakes...but they are not there.
 

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Come on now, that is your stance here? I get that you are super detailed and want things on your truck to perform better than when it was new, but this is a stretch.

I want to see a pic of this 10k lb boat, that when in reverse, on the boat ramp, in 4wd, you need the trailer brakes.

If you want to be realistic, I can tell you about the day I took 6 k-rails on a triple axle down hills with zero trailer brakes.
 

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Discussion Starter #10
No need to get all worked up.....for a mod, you sure seem to take things way to personal.

The boat is around 6,000lbs. The camper pushes 10,000lbs loaded. Yes, I like stuff to work right....some people are like that. Better than new? Nope...just work like they are supposed to. The problem is that the TBC does work like it did when it was new......that's why they came out with a tech bulletin explaining to people that you have next to no trailer brakes when you are under 15mph.

No other aftermarket TBC I've ever used, or heard of people using will not let you actuate the brakes are slow speeds.....thats just stupid, what's the reasoning behind that train of thought?

My post was mostly created to see if there was any way to modify the OEM TBC or do some other fix to make it work the breaks at speeds under 15mph.

No need to get all worked up. :wink:
 

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Discussion Starter #13
lucky me
my 6000 lbs boat uses surge brakes lol

and Heavy does not get "worked up" he is always like this
Yeah....mine had surge brakes but they were horrible. I swapped them out for electric brakes.....stops much better (when the TBC gives them power).

Pulling the boat doesn't bother me as much....it's light enough to stop even without trailer brakes. The camper is what bothers me....the campsites in my area are pretty hilly......it's not fun to stop when you don't have trailer brakes under 15mpg. I'm surprised they actually designed it to function like that....what would Ford's reasoning be??

And yes.....I've figured out that he's always like that. :wink:
 

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Discussion Starter #15 (Edited)
As far as I can tell.....when you manually activate them, you have no brakes at all. Does the system put out half a volt or some other minute about of voltage? Maybe......but half a volt might as well be zero volts. When I first bought the truck I actually thought the TBC was faulty because when I hooked my trailer up and manually worked the brakes ..nothing happened. But then when I would get out on the road, they started working.

I would understand if the automatic function (just using the brake pedal) would reduce volts at slow speeds.......as long as you still had full power if you manually actuated them......but you have next to zero braking power.....even though the controller shows full green bars (power output).

Yes, a fix/hack would be nice. Even at 10mph.....if you are pulling a heavy load and need to stop quick, the fact that you can't get power to the trailer brakes is insane......
 

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it takes a special tester to check the Ford reduced TBC output ans it had failed many roadside safety inspections because the inspectors did not know about this "better idea"
Bismic may have posted the pdf for that ?

i like the integration of the TBC but if i used the e trailer brakes I would probably piggyback a manual full volt slider
 

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Discussion Starter #17
it takes a special tester to check the Ford reduced TBC output ans it had failed many roadside safety inspections because the inspectors did not know about this "better idea"
Bismic may have posted the pdf for that ?

i like the integration of the TBC but if i used the e trailer brakes I would probably piggyback a manual full volt slider
I've thought about trying to bypass the OEM TBC and install an aftermarket one......but I'm just wondering how easy that would be to do since the factory TBC is tied into the trucks computer. Other than the "no brakes under 10mph" issue....the factory TBC actually works great! It's nice and smooth, and I don't constantly have to tinker with it like I have to with most aftermarket ones I've used. Sure would be nice to just figure out a way where I can still get braking power at slow speeds.

Did all the 03-07 factory TBC's do that "reduced braking power at slow speeds" thing....or just the 05's?
 

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you will lose all the integration of the ITBC if you go standalone but it may be best for your needs ?

i think it is BS that you can't just flip the manual slider to straighten out a truck sliding on the road under the speed dictated by the tbc
 

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Discussion Starter #20
I'm still trying to think of a reason why you would WANT to reduce trailer brake power and slow speeds. If your foot is light on the brake.....the trailer brakes should be on light. If you are heavy on the brakes, then trailer brakes should be on heavy.

Just because you are under 10-15mph doesn't mean that you don't need trailer brakes to help the truck stop. The logic there is very confusing......
 
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