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Discussion Starter #1
I have Electric over Hydraulic brakes on my load rite trailer, only 2 years old, with a Titan Brake Rite EHB (the control board is in the unit itself). Truck is GMC Sierra with factory ITBC. Everything was working fine for 2 years. About 2 weeks ago I went to use the trailer and the brakes wouldn't work at all. After fiddling and checkign contacts etc., I get intermittent but still incorrect function. At best, they now only work if I apply about half pressure. This is true whether I use the brake pedal or the manual lever on the ITBC. So if you step on the brakes to stop, as the ITBC indicator goes up the brakes start to grab but as the indicator passes about halfway the brakes release and I can hear the brake pump on the actuator stop too. Same thing happens on the manual controller. Sometimes if I hold the brakes or manual lever just under halfway the actuator motor will stay running and I do get some braking. But other times I can't even get it to do anything no matter what I try... the ITBC indicates either partial or full braking gain depending on what I'm trying at that moment, but there's no actuator motor sound and no braking at all. So it's really intermittent but never really works properly.

I'm beginning to suspect it's on the truck side. How do I test the ITBC and the truck? I've cleaned all the contacts, replaced the breakaway batteryt, I always used dielectric grease, and when I start the truck the ITBC says "Trailer Conencted". The back of the 7 pin near the spare tire seems good but tomorrow I'm going to try unwrapping it and checking those connections too.

I had run the "3 wire test" last week on the actuator using a battery, and I was only getting a momentary actuation. And I got nothing when pulling the breakaway pin (on a new fully charged battery). So that seems to point to the actuator. But today I was getting sustained braking when applying the brakes halfway as I said above, so now I'm really scratching my head. Titan is sending me a warranty replacement unit (awesome company!) but I want to ensure my controller is working properly too before I install the new unit.

Any ideas? Thanks for the help!
 

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Welcome to DieselPlace

Please tell us more about the truck ( Year, Make, and Model) and list any known mods.

(y)
 

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Discussion Starter #4
Sorry, forgot that... truck is 2011 GMC Sierra work truck. No mods that I'm aware of, using factory installed ITBC. And Ron, yes, I'm familiar with that adaptor. When I got the trailer I thought I'd need it, but it worked fine without it so I never ordered it, and it worked well for 2 years. And last week when I had the actuator cover off and was doing the 3 wire test, I noticed there's part in there that looks almost exactly like that adaptor, with a white and blue wire. So maybe that's built-in to my Titan model...? Thanks for the replies!
 

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Could the itbc relay be on the way out. It is separate from the itbc module. Mine all swell from corrosion and always visibly compromised.
 

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Discussion Starter #6
Could the itbc relay be on the way out. It is separate from the itbc module. Mine all swell from corrosion and always visibly compromised.
Thanks heymccall, definitely worth checking, where exactly is the relay, and can I disconnect it to inspect?
 
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