I have a 2001 Ford F-150 4WD w/ 5.4L V-8 and the tow package. The problem I have is when I hook it up to my boat and put it in reverse, the surge brakes on the trailer lock up and I can not go backwards. It does not happen with my Sequoia or my friends Dodge 2500 that we used the other day. I had the electrical on the tow portion of the F-150 checked out at the Ford dealership and they said it was fine and that it all checked out. I have checked with some trailer shops with no success. Does anyone have any ideas what the fix would be?

 

Surge brakes work off of compression between the hitch coupler and the trailer tongue. When that portion of the tongue/coupler is compressed it applies brakes. So, when you hit the brakes on the truck, the surge master cylinder compresses between the load of the trailer and the coupler....and in turn applies brake pressure on the trailer. When you back up you are applying compression and the brakes are activating. If you do this slowly it should not apply the brakes. A reason that it might apply on one vehicle vs. another is hitch height, applying more pressure because of an incorrect hitch angle or one vehicle is backing up faster than others appling the brakes.

Surge brakes have nothing to do with the tow vehicles electrical or mechanical function.

 

Do you have surge activated drum brakes or disc brakes? If you have the discs on your trailer and do not have the correct (flat 5) wiring in working order on the truck, the trailer brakes will lock up in reverse. The blue lead on the flat 5 harness is hooked to your backup lamps and activates a solenoid that blocks the trailer brake circuit on disc brakes to allow you to back up.

 

Do you have your reverse light relay plugged in? The surge brakes may only turn off it if gets signal that it's in reverse.

 

Check your solenoid, you should hear a click when you put it in reverse. If you don't then it's either a bad solenoid or electrical connection.

 

It may be the age of the trailer. I had a 1982 Jayco camper that had no surge brake lock out. Later models had a mechanical "switch" on the trailer master cylinder for reversing. Mine, alas, did not. The fix was to have my shop install a valve on the trailer brake line just after the master cylinder that was controlled by an electric solinoid. The solinoid was spliced into the backing lights. Backing lights go on, solinoid shuts the valve, no brakes.
It cost about a hundred bucks, but enabled me to back the trailer up my steep driveway.

 

I am having the same problem with my 2001 expedition and possible my 98 f150 will find out wednesday when I pull my boat. But a temporary fix to the problem is when you are ready to back your trailer up is to get out and turn the 5 flat plug in around and plug it back in this will leave one male and female plug empty but will be putting the blue wire in a position to recieve some current. after you turn the plug around turn your headlights on and voila your brakes now will be released. I am contemplating just running it like this since I am not pulling my boat everyday.