I have a 2001 F250 PSD and I noticed that my brake controller was no longer working the other day so I purchased a new one. When I went to install it I check the voltage in the factory wire harness for the brake controller and in the blue wire (trailer feed) I was getting 2.4 volts without hitting the brake and when hitting the brake I was only getting approximatly 6.3 volts (all with the truck running.) In the instructions for the brake controller it shows that I am suppose to have 12 volts when brake is pressed and to confirm we checked it on my dads Excursion and it was reading 11.9 volts pressed and 0 volts with no brake. I know there is an issue somewhere I just cant seem to find it and I was wondering whether anyone had any suggestions on how to troubleshoot or has had this issue before.

The brake contoller I purchased is Activator III 1-4 Axle Brake Control - #5520

heres the link to the thread i posted on the 7.3 section before I moved it here: https://www.ford-trucks.com/forums/9...ge-issues.html

 

Check and make sure that there is no corrosion on your plug connections. This would include the trailer plug, pluf on the truck, and the male/female connection for the trailer plug located behind your rear bumper near the spare tire.

 

Morning,

The most likely culprit is the ground, so pay particular attention to the white lead.

The one important thought I will share is you can not check out many brake controllers at all by using a multimeter at the contacts on the truck. The controllers has to "see" a "load" to function correctly, and a multimeter does not create an ample load.

I do not know if that is the case with your controller. It is increasingly common, however, with modern controllers. If your controller falls in that category, the voltage readings you are seeing are meaningless and tell you nothing at all about the controller.

When I work on brake controllers, I use a tester that emulates all of the resistances (loads) found on a standard trailer and I test brake output with amperage, not voltage. Many RV dealers have the same device and since it takes only a minute, the ones near me don't even charge to plug it in and read the outputs. If you do not want to go that route, pick up one of the seven pin testers readily available at many automotive stores. Any time you see a technician using a multimeter to test a brake controller, be very careful.

You may not be able to compare readings between vehicles unless you are comparing the same controller mounted in the same vehicle.

I guess this is my very long winded way of saying not to try to fix it until you're sure it is broken and using a multimeter to test brake controllers can get you chasing ghosts.


Best of luck,

Steve

 

I took the original brake controller out because when I hooked my truck to my dads snowmobile trailer the electric brakes werent working and the light on the brake controller was flickering and it did this when I applied the brakes without a trailer hooked to my truck. So I took the controller and for the heck of it I checked the wires in the factory wire harness and the blue wire that is for the trailer feed was showing 2 volts without the brake applied and with it applied there was 6 volts. I knew that couldnt be right so I looked at the new brake controllers diagram and it showed that I am suppose to have 12 volts when the brake is applied and 0 when not. So I have no idea where or what to look for to solve this issue. Does anyone have a wiring diagram of the brake controller?

 

Derek,

All brake controllers I know of are just four wires and all are wired the same. If your controller has a plug, you can purchase the controller to truck plug and just plug it into your truck, for most pick ups, without doing any wiring. I am not sure how you are picking up two volts with no activation. Wiring diagrams are pretty easy to find online.

Since you have a digital troubleshooter on this controller, what does it read when you activate the controller manually with no trailer attached?

Steve