I was going to post in towing and hauling but this seems more like an electrical issue

SSCULLY..I hope you can provide a direction to investigate.

'01 SCREW with trailer towing package. Tekonsha Voyager brake contoller installed with the 2 relays. I have towed OK with this before. Today I hook up my trailer and the brakes stay locked. I test my 7 pin and find that my brake tab has constant 12V. I try new relays, check all the fuses (I double checked with the diagrams for controller and Ford's supplementary instructions, just don't remember the numbers now) AND I hooked up TWO other controllers. Same results, constant brake voltage.

If I pull the large relay in the PJB, I can have lights and blinkers and brake lights. But no trailer brakes or reverse lights on trailer.

What should I check?

Thanks for looking.

 

After having changed the brake controller, the next thing to look at, is the stop lamp input to the brake controller.

On the controller pigtail, this is the light green wire


This is fed directly from the BPP ( Brake Pedal Position ) switch.



With 3 controllers having the same issue, I would think this to be the next place to look.

There is no relay for the trailer brakes from the controller to the 7 pin trailer tow adapter ( Dark Blue wire )



Not sure what relay you are pulling to kill off the trailer brakes, this almost sounds like the trailer tow battery charge relay.


You are metering the correct pin for the trailer brakes ( dumb question, but the pulling relay comment makes me have to ask .

 

SScully, WOW again.

Yes, I am metering correctly for the DB brake wire at my rear bumper. I am correctly wired at the 7 pin factory plug. No problems as far as wiring going.

Also, you are correct in my removing the trailer brake/charging relay - sorry I didn't clarify.

When you say to check the stop lamp input TO the controller, (the light green wire) What should I look for? Should it be 12V when brake is pressed or off? Should I check it on the truck side or the controller side? Dumb question I know. With the brake/charging relay removed, I still have all my marker lites, tail lites, blinkers and brake lites. Just no electric brakes or charging voltage.

Also, on my Tekonsha pigtail, I only have 4 wires. In the diagram you gave I see a brown wire for headlamp running lamps. I have never seen this wire on any brake controller I have used.

So, after all that, I guess I just need to know what to look for when testing the green wire and how to test.

Thanks

 

The light green wire should be a positive trigger, so when you press on the brake pedal, you should get + 12 V DC.

Just unplug the pigtail & brake controller, and meter it on the Ford side of the brake controller pigtail.

The Tekonsha pigtail should have the 6 pin ( Ford truck side ), but if this only has 4 wires that is OK, so there will be 2 empty pin slots on the side that plugs into the truck.

Some controllers have illuminated displays, which is what the brown wire for the parking lamp is for.

Considering the Dark Blue wire is a direct shot, the only other thing that I can think of is a chaffed wire from the trailer tow battery charge circuit and the trailer brake circuit.

That would be easy enough to check next, with everything installed as the trailer tow adapter instructions make note of ( i.e. reinstall the relay you pulled ), unplug the brake controller, and at the truck side of the brake controller pigtail, check the dark blue wire for voltage with the key in the run position.
If this has +12 V with the brake controller unplugged, the problem is downstream of the brake controller, and it would be time to follow the wires under the dash, through the driver's side kick panel, and down the driver's side frame rail.

The other test is with the brake controller unplugged, key in the off position, meter from the trailer tow battery charge pin to the trailer brake pin with resistance setting. This should be infinity.

Start with the BPP test 1st, then move onto this.