I am having a problem with our 2005 F-250 diesel with the Ford Tow Command brake controller. I have had the truck in the shop twice to have the dealer look at the system. They told me that they can find nothing wrong with the system. We went on a trip to Virginia and while on I-85, the truck dropping out of cruise control, the ABS brake light came on, and the trailer brakes went away. Using the manual slider, I could apply the brakes but that was all. I had rewired the trailer with #12 wires and put in an new weatherproof ez-connector. The system worked fine until the truck had been running about eight hours. Then suddenly, the truck drops out of crusie control, ABS lights, and the trailer brakes are gone. Pulled into a rest stop, checked the trailer connection, it was good, and looked under the trailer to see if brake wires had been damaged. Nothing. Shut the truck off, started it again, the controller works, and no ABS light. About thirty minutes later, same things again. Have to use the manual slider to apply trailer brakes. Get to campground, unhook, check fuses, wire connections, look under dash for anything loose, and find nothing. This is the later model controller as the truck was made in later 2005. Any ideas?

Probably should post this in the tow vehicle section. Why do you think its the controller and not the ABS circuit?

Nothing worse than intermittent problems. Hate to say it but you probably will not find it until it fails completely. Trying to troubleshoot something when it is working correctly rarely results in finding and repairing the problem.You might go over to the Ford Truck Enthusiast web site and ask your question. Lots of good Ford truck help there.

Has the instrument cluster ever been out of the truck? Everything goes through it.You need to take it to a place that can pull the ABS codes. If the light has been on then it will have a code. It could be tied into the integrated controller.

Try f150online.com allot of members for all model Ford trucks you will prob find your answer there.

Check the brake wires where they go through the backing plate to the magnet. Very often a wire will rub until the insulation is worn off causing a short or amperage leakage.

Ford Tow Command | Good Sam Community

ken_white
Explorer
Sep 24, 2013
Probably should post this in the tow vehicle section.

Why do you think its the controller and not the ABS circuit?
BB_TX
Nomad
Sep 24, 2013
Nothing worse than intermittent problems. Hate to say it but you probably will not find it until it fails completely. Trying to troubleshoot something when it is working correctly rarely results in finding and repairing the problem.
You might go over to the Ford Truck Enthusiast web site and ask your question. Lots of good Ford truck help there.
transamz9
Explorer
Sep 24, 2013
Has the instrument cluster ever been out of the truck? Everything goes through it.

You need to take it to a place that can pull the ABS codes. If the light has been on then it will have a code. It could be tied into the integrated controller.
Bigmoss
Explorer
Sep 24, 2013
Try f150online.com allot of members for all model Ford trucks you will prob find your answer there.
I_am_still_wayn
Explorer
Sep 24, 2013
Check the brake wires where they go through the backing plate to the magnet. Very often a wire will rub until the insulation is worn off causing a short or amperage leakage.
45Ricochet
Explorer
Sep 24, 2013
Most auto part stores will pull your codes for free. If you threw a CEL it threw a code.
LostinAZ
Explorer
Sep 24, 2013
45Ricochet wrote:
Most auto part stores will pull your codes for free. If you threw a CEL it threw a code.

Many auto parts stores use a limited capability code reader and may not be able to pick up all error codes. Secondly in our recent situation with a intermittent dash light indication of an ABS failure even the Ford dealer could only locate the error code if it was present at the time of the check. Apparently the ABS error code isn't stored. The Auto Parts stores were not able to read it at all.
Road_Runners
Explorer
Sep 24, 2013
I had that problem once a few years ago. I finally got rid of the problem by taking the female connector apart and cleaning the electrodes.
TakingThe5th
Explorer
Sep 24, 2013
I have had the same problem with my 2005 F350 since new. Ford dealer gave me the same story-everything was supposedly OK. I isolated the problem to using the cruise control-if I don't use it I have no problems. So when I use it I reset it every 15 minutes or so. Lousy, but it works.

I asked the Ford dealer to install a 7-pin bed plug and they refused-said it would cause problems-but if I wanted to do it I should use heavy low-resistance wire and solder the connections.

Somehow circuit resistance plays into the problem, but only when the cruise control is on.
TakingThe5th
Explorer
Sep 25, 2013
Road Runners wrote:
I had that problem once a few years ago. I finally got rid of the problem by taking the female connector apart and cleaning the electrodes.

I also apply dielectric grease to both plugs which seems to help keep things clean.