'O5 SD. Made 2 1500 mile round trips now from MN to MO. Towing car hauler with misc garage stuff. Trailer is new and of course the wiring is new. Brakes and lights work like they are supposed to. Approx 10 (more or less) times per day the red light that looks like a trailer, will light up and the "bell" will ring for two or three or four times then the warning stops and all is looking normal til the next time. The light and warning are supposed to mean the trailer connection is broken. But as this is happening I have tried the trailer brakes manually and they work just fine. Can't predict when this will happen but seems more likely within a couple minutes of starting out and going slow through towns. However not necessarily so, as it will also do that at any time such as cruising down the road doing nothing, no braking, no acceleration just going steady speed.

Had it to my Ford dealer yesterday. (Also did the recall and oil change and tire rotation) I don't think they understood the problem. Or don't understand the conroller. They said they checked it and it was a problem with the wiring on my topper and that they disconnected the cab brake light as there should not be that one and the one on back of topper working at the same time. They just removed the bulb in the cab brake light. Also they said they test drove it and it was ok.
I hooked up the trailer as soon as I got home from dealer and the warning came on before I got out of the driveway and one other time during a 4 mile drive.
I am suspicious about what they did. Even before I left the dealer, and told them so. First of all there NEVER was a problem like it acting up during braking. Second the "test drive" ! Good grief ! They could drive it a million miles and it would do nothing without having trailer hooked up!
I had hoped they could check it out and although chances are slim they would catch it "acting up" maybe they could if they had the right test procedure for the controller.
I'll probably take it back and talk to them as they charged $89.00 for nothing. But the dealer is 50 miles away so I can't run over there every day. I fear it will be easy for them to say it's a trailer problem and a trailer person (my trailer dealer sold out and went back to college so no point asking him) will say it's Fords problem. Like I said everything seems to work fine even when the red light and alarm are going off but it is very annoying and driving me nuts.
I have had the truck sitting at idle with trailer connected and had my wife watch the controller while I wiggled the wiring connection and cord (7 prong connection) every which way and nothing happens. Could it be trailer wiring? Why would it do that off and on for no reason? (that I can figure out anyway)
Hope there is someone out there who understands these things and can help!
Thank you!

 

This is just a guess but it sounds like you might have a grounding problem. If the trailer control loses its ground , that would cause the alarm to go off.
I have had grounding problems in the past and had to run a heavy guage wire
from the negative post of my tow vehicle's battery right to my trailer wiring.
You may find you have a poor ground on your trailer and it is only grounding through the hitch ball. This is a poor ground at best. Good luck . Wrenchtraveller

 

Thanks for the idea. I'll check that out. Appreciate any and all ideas on this problem.

 

I think wrench has the answer. Many cases the ground connection is made through the ball hitch connection. If there is rust on the ball or hitch surface it will take a few miles of driving to clean it up. Good luck.

 

If that does not work, give Tekonsha a call. They are the designers/makers of the Ford braking setup (from what I was told by a friend at Ford). I'm sure someone there might know about it.

I owuld first check to see if the trailer has a wire for ground or if it is ball grounded like Wrenchtraveller said. Does your trailre have 7 prong wiring, or did you have to use an adapter to plug to the truck?

 

CobraXP, thanks for the reply. I tried once to reply to yours and got a message,
"Your message is too short". "Add at least 10 charactors". Don't know what thats all about! So will try again.

Thanks for the reply. The trailer came with an adaptor about 3 ft long. On one end is the older style flat type 5 prong that plugs into the trailer wiring and on the other end is the round 7 prong that plugs into the round connection on the Ford. The flat type connection (5 prong) on the pickup is not used and has a rubber plug in it to keep it clean.
Does this make any sense?
We will be towing approx 1600 miles each week for the next two months whether it works right or not, but sure would like to not get the alarm all the time!
I will try the seperate ground if that don't work will give the Teshonka people a call. I don't think anyone at Ford will be much help.
Many thanks!

 

I think if it were mine, I would remove the connector on the trailer and install one that fits the one on the pickup. Should be fairly straight forward to do. I would use a test light on the trailer wiring to see what is what, and wire it back.

John

 

I had a similar problem. Turned out to be the adaptor from the 7 prong on the truch to the 6 prong on the trailer. The first adaptor I bought was apparently wired differently than the truck/trailer. The problem was as follows: the lights worked, the brakes were locked, the "trailer disconnected" message displayed. I exchanged the adaptor for a different brand and things have worked perfectly since. I would have thought the internal wiring of the adaptors would be standard. Either this is not the case or I got a bad one.

 

Ok I might try that. During all my warning light flashing and bell ringing episodes, the brakes have worked normally. A couple times with the warning going off, I have tried the trailer brakes using the manual slider and the brakes worked fine. I am not able to see from the drivers seat if the lights are all working at that time but assume they are.
Thanks for your reply! All suggestions welcome.
We are heading out in the morning for a 1600+ round trip. Car hauler with car and misc wiegh over 6000 lb. Plus maybe a 1000 lb in pickup box. This will be the heaviest tow so far and will no doubt be the lowest gas mileage.

 

On re-reading I tend to agree with the suggestion of a short, due to the symptoms being intermittent with normal function between events.

 

Just got back from a 1600 + mile trip. Three days of driving. Brake controller warning still comes on whenever it wants to. Seems to be no rhyme or reason for when it alarms. No predictable time for it to happen that I can figure out. But it will alarm approx 10+ times per day. Some times going through a town it may alarm 2 or three times. Sometimes it will be many hours before it "alarms" again.
At no time have I ever been able to detect anything wrong with trailer brakes or anything even at the time I get the alarm.
I am thinking it's in the controller it self. But don't know how to check to find out. Seems Ford would have a way to "simulate" a hooked up trailer and have it on test for several hours. I don't think they (Ford) have that capability.
Maybe some trailer dealer/repair place might.

 

I think you hit the nail on the head. I would go to an RV dealer with a competent service dept. They are much more accustomed to dealing with this type of troubleshooting.

 

Ok. I'm going to check with some RV places as soon as I can.

 

Hi, Did you ever get this problem resolved??? We are experiencing the same problem with our '06 F350 truck and 5th wheel trailer. Thanks.

 

Ditto. I have a 2006 psd with a fifth wheel as well and am having a similiar problem. The only difference is that when mine goes into error mode, I lose my trailer brakes. I haven't been able to get to the dealer as yet, I thought I would check the forums to see if anyone else was experiencing the same issue. Obviously I'm not alone.