Originally Posted by RV_Tech

The piece of the puzzle I see missing in both of the above cases is a measure of how many amps the controller is putting out. As many of you know, I have long been less enthused about Ford's ITB controller because it pales in comparions to quality aftermarket controllers in terms of built-in diagnostics (and yes I do have an ITB in one of my trucks, so I am familiar with its operation, and no, I am not impressed).

I no longer think these are harness issues given the bountiful information preceding. What if it is simply the case the controllers are going down in high demand or repeated high demand situations? I may be wrong, but it sounds like the error messages are coming during operation, not while sitting still. In the OP's case, the controller works with a small trailer, but not a big trailer in terms of demand, possibly?

With intermittent problems, it is always the case that it takes more to diagnose the problem. What I would do in both of these cases is take my tester box with its twenty foot lead and plug it in. The I would say "let's go for a ride". I would dial up the controller to max so it was going for full output with hard stops and watch my monitor box while we went for a ride. That way I could see exactly what was happening when the truck brakes were activated and what was going on when the error messages came up. I don't know what it would show, but I sure would like to. I am going to assume here that in both cases the posters really do know what they are doing and have done all the obvious. I also am going to assume in the second case, at least one of the RV techs was reasonable in their diagnostic attempt. Doing what I am suggesting would really lay the issue of is it truck or trailer to rest because I would essentially have the trailer brakes sitting inside my monitor box in my lap.

If, and only if all was good there, would I rip the wiring out of the trailer and redo all or some of it.

When you remove what isn't, all that is left is what is. I may be a thousand miles off, but what if the reason the problems don't appear to be one of the common things is because they really aren't? One of things I have often found is sometimes techs stick too closely to established protocol. Once in a while thinking outside the box is important.

Just my two cents worth in what I find to be really challenging situations.

Steve

Originally Posted by rvpuller

Like I said Steve I don't own a truck with a ITB installed so I don't know what it has for diagnostics, but on my Brakesmart I can set it so it has the amperage and voltage displayed when the controller is in operation so it makes easier to find problems but when there is a short it shuts down the controller output as soon as it detects one so no brakes but if you have a short you won't have brakes anyway. Before I buy a truck with a ITB I'm going to take a close look at its operation and I may keep my Brakesmart.

Denny

Originally Posted by RV_Tech

Denny,

Personally I would keep the Brakesmart. My aftermarket controller also will read amps and volts, something I regard as invaluable, but which my ITB controller will not do. You and I both know how simple diagnostics are with the right equipment.

One of the things that I keep seeing is the number of aftermarket brake controllers completely dwarfs the number of Ford's integrated controllers in circulation, but the problems with the ITB must run 50 to 1 in this forum and a lot of the folks having them are pretty darn competent.

And, as has been frequently discussed in the forum, it doesn't even seem like the Ford techs know how to troubleshoot them beyond testing in static mode, which tells you almost nothing. Reminds me of the crap I have to go through everytime I have to troubleshoot one of the big diesel motor homes.

Steve

Originally Posted by phantomphixer

OK the final report on toy hauler wiring.


Drum roll please----- Cut out the old brake wires and routed in new wiring. Had a large roll of 10 gauge automotive wire so I used that. Hooked up truck and away I went. NO INTERMITTANTS- NO TRAILER FAULT- NO TRAILER DISCONNECTED indications. Brakes worked as advertised. Finally.
Left the old wires in the axles and tyrapped the new ones to the axle.
Thanx for all the suggestions, ideas and encouragment.