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Let's take it from the top. I have been having problems with my trailer brakes on my two axle trailer. After about two hours into a trip my brakes would intermittently come and go. My single axle trailer worked fine. Suspecting it was my brake controller I purchased a Prodigy brake controller. Still having the same issues but the good news is that the Prodigy unit displays a code that says my trailer is connected and the unit loses connection to battery ground. This is installed in a 2003 F350 Lariat Super Duty. Has anyone else had the same problems with possible solutions?
Last edited by cljimmy72; Jun 13, 2006 at 06:47 PM.
Are the contacts on the truck plug or trailer plug corroded, maybe need cleaning? Is this happening when it rains (everything is wet) and possibly shorting out?
But is it wired nice and tight? I have seen plugs that are not corroded but when you take the plug apart, you see that one wire is barely hanging on. I'd open up the plug and make sure the wires are good. Then the other end.
That sounds like a ground problem to me. Make sure that you have a ground wire coming out from the trailer's plug and connected to the trailer's frame. If that fails, make sure all the terminals are tight on the trailer plug.
Without a good ground through wires, it'll try and ground through the hitch gear. As the trailer moves around, the resistance of that connection will go all over the place and that means the amount of voltage going to those magnets will also go all over the place and won't stay where the brake controller sets it at.
Already opened up the plug from the trailer to make sure everything was tight. That was the first thing I checked with the old controller still in service. I'll check the ground wire on the trailer itself.
I've got almost the same problem and I've got a Prodigy controller in my 04 250 SD Lariat. I've used it for the last year towing my horse trailer with no problems, but towing back from the first show last month I noticed the 'nc' flashing (meaning no connection)...and it goes from connected to no connection as you drive along. I have all other functions (turn signals, flashers, lights, brake lights) but brakes only intermittently. I've replaced the plug-in from the trailer, cleaned connections, chased wires down, checked wiring harness in the truck...can't find anything. When I depress the brake pedal you can hear a hum or buzzing back by the rear axle brakes, so it's getting some kind of voltage (?). I called Prodigy and they said the 'nc' means there's a loose connection somewhere, but I sure can't find it. I plugged it in yesterday without it being hitched up and it showed 'nc'...I pushed the break pedal and it showed connected...then went back to 'nc', then back to connected, where it stayed until I unplugged the trailer....I'm stumped!!
Still sounds like a ground problem for both. Make a jumper out of 12ga wire and hook it to bare metal on TV and trailer with trailer plugged in and unhitched; if the display shows normal you've found the problem.
Today I called Tekonsha who made the Prodigy controller for a little technical advice. They told me that the code I was getting (og) means that I have lost ground to the controller not the trailer. Sure is fun tracing out an intermittent problem. Checked the ground wire coming to the connector for the brake unit and all is fine. Seems to be as the amperage load increases the ground drops out. Found a couple of questionable connections-slightly corroded- under the hood coming off the negative terminal on the battery. Cleaned them but did not take my trailer for a ride since it rained here most of the day and I have my show truck loaded on the back all nice and clean for a show on Sunday. Sure hope this is the cause. If not the next step is to run a jumper from the negative side of the battery to the white (ground) connection of the controller. Sure don't want to tear into the wiring harness behind the dash. Tons of wires there. Thanks for everybody's help. Maybe we'll get it yet!!!!
When you put the Prodigy in, did you buy the premade harness or did you use Ford's pigtail harness? If you soldered or crimped the wires there, there's a possibility of a cold joint or loose crimp.
I am tempted to still go with the ground problem. I do have one other idea if that fails, though. When you were chasing down those wires, did you check out at each connection to the brakes themselves on that trailer? If you had a damaged wire at one of the magnets, that just might do what you're talking about here. I don't know if the Prodigy can catch it fast enough to give you the shorted magnet code.
Another idea might be to hook up an ohm meter and measure the resistance between the brake and ground pin on that trailer. This would help show up a wire that might have a lot of broken strands in it.
I checked the wires only up to where they insert into the rear of the wheel housing...no problems...didn't pull the wheels. I will try to jump the ground tomorrow and see if that works...it's got to be something that is loose or frayed as I have an intermittent connection. Thanks for your help and suggestions! I will let you know what I find.
Finally I found my problem. Just wanted to let you all know what I found. Traced it down to the left front wheel on the trailer. Removed the drum and found that the mounting arm for the electro-magnet had a sharp edge on it and it had cut into the hot wire going to the magnet as it activated. Some shrink tubing, rerouting of the wires and a little filing on that sharp edge and I'm good to go. Thanks for all your advice. Sure wasn't a easy one to solve.