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Check your trailer connector on the truck for moisture/corrosion. If nothing found, you've probably got a cold solder joint inside the TBC that's broken. You have 3 choices:

1. Pull TBC and inspect all cold solder joints - repair if anything found
2. Order a new one from Ford ($PENDY!)
3. Send yours in for repair 2005 - 2007 Ford Super Duty Trailer Brake Controller Repair

-jokester
 

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Discussion Starter · #3 ·
Check your trailer connector on the truck for moisture/corrosion. If nothing found, you've probably got a cold solder joint inside the TBC that's broken. You have 3 choices:

1. Pull TBC and inspect all cold solder joints - repair if anything found
2. Order a new one from Ford ($PENDY!)
3. Send yours in for repair 2005 - 2007 Ford Super Duty Trailer Brake Controller Repair

-jokester
If corrosion clean it any thing to spray or lube it up with? Thanks
 

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If it were me, I'd test your connector pins on the truck side first before disassembling. You might not even need to go that far as to clean it.

If you do decide to clean everything, disconnect both batteries & take your connector apart as much as you can to get to the wires & pins. Make sure to clean off all wires & pins with a small wire brush or brass brush, some brake kleen, and blow dry with air before reassembling and hooking up the batteries again. I'd also use a dab of dielectric grease to keep out moisture.

Others probably have better ideas how to clean it though. This is just the way I would do it with what little knowledge I have.

-jokester
 
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2005 F250 FX4 Lariat CCSB - ARP studs, EGR deleted, IPR coolant filter, PHP FICM tunes.
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Funny thing I learned about the factory TBC while picking up a new (to us) camper.

Factory TBC won't apply brakes if the truck isn't moving above a (so far unknown) speed.

The camper dealer hooked us up to our new camper on the ramp outside their shop, which has a slight down grade.

I started the truck, put in neutral, and allowed it to start rolling forward, driven by gravity. I manually applied brakes with the TBC, and nothing happened. On the Tekonsha aftermarket TBC in my F150, the brakes would have engaged.

The camper dealer's technicians confirmed with a test box that no power was being applied to the brakes. They also confirmed, using the test box, that applying current to the brakes engaged them.

A Google search on the symptoms caused me to try a different test - drive the rig around their lot, while manually applying trailer brakes. Lo and behold, the brakes worked! And have done so ever since.

It would be awesome if someone like @FordDoctor could share the details of the factory TBC operation.
 
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@MtnTallPaul - I am assuming you are asking about your 2005 F250. There is very little about "using" the system other than the controls and what they do in the workshop manual. When I have more time, I will do more reading. Keep in mind that the auxiliary braking systems have evolved and changed with the Super Duty models over the years so advice coming from a 2017 MY Super Duty may not be accurate. I also have NO, I repeat, NO EXPERIENCE towing and I never have a customer's trailer on hand to test.

I always assumed that the manual paddle is functional at all speeds including when stopped. One possibility is that the trialer connection was lost at some point before moving. The trailer indicator on the controller would turn red or begin flashing if connection is lost while moving.

I'll dig some more... gotta head off to work!
 

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If it were me, I'd test your connector pins on the truck side first before disassembling. You might not even need to go that far as to clean it.

If you do decide to clean everything, disconnect both batteries & take your connector apart as much as you can to get to the wires & pins. Make sure to clean off all wires & pins with a small wire brush or brass brush, some brake kleen, and blow dry with air before reassembling and hooking up the batteries again. I'd also use a dab of dielectric grease to keep out moisture.

Others probably have better ideas how to clean it though. This is just the way I would do it with what little knowledge I have.

-jokester
Good advice, except I certainly wouldn't advise brake kleen, that can soften and damage insulation. Use WD40, it's low viscosity, water displacing, and lubricating properties can do a reasonable job at cleaning electrical components without damage.
 

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Good advice, except I certainly wouldn't advise brake kleen, that can soften and damage insulation. Use WD40, it's low viscosity, water displacing, and lubricating properties can do a reasonable job at cleaning electrical components without damage.
Wait...you clean the insulation? :D

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