help, trailer brakes locked up when plugged in
 

96 F250 PSD

12' owens open 5k trailer with brakes.

-DO NOT HAVE THE AUXILIARY BATTERY INSTALLED

- last weekend i converted the trailer harness truck side from 7 round to flat. the old harness had two wires not connected. i voltage checked and hooked up the tail, turns and brakes. i tested it that day and all the light functions worked including brake lights. i did not however try driving it. well today when starting work. i plugged them in and the thing wont move. unplug the trailer and it moves fine.

so forum, does it seem like its a trailer,brake controller issue, or wiring issue?

really need this fixed up,id rather not pay someone else to fix it.

thanks,
-Juan

It sounds like you didn't wire something in the plug correctly. Did you wire in the 12v circuit?

Here is a good set of plug and socket diagrams.

Trailer Wiring Diagrams | etrailer.com

hmmm, i wired in 5 wires (tail, left, right, ground, brake) missed the auxilary, very well,will fix it all up tomorrow afternoon!!

will report back!

thanks!

how would i test for that? truck should be running? should the trailer be plugged in?

As far as I know you have to be getting power to the brakes directly. So your controller is wired incorrect or is defective, or you have the wires wrong at the plug. The only other thing but they would be locked all the time is they are seized up in the applied position.

Craig

Check and see if the pin for the emergency brakes has been pulled. If it rolls without being plugged in and locks up when it is plugged then it really sounds like that may be the problem. Once that pin is pulled, it uses available power to lock the brakes up. You might also try hooling up a battery and not plugging it into the truck. If the brakes are locked then (battery wired in, trucjk unplugged) that's the problem

The aux wire is usually used to re-charge the trailer battery.

the light on the controller doesn't light up. its a voyager.

i can go backwards and it rolls fine, put it in drive and bam, damn diesel wont pull that trailer!!

would it make sense that it is wired right seeing as the tail lights work, turn signals work,even the brakes. im talking just the way they light up.

any other opinions? is there a way to test the controller?

hook up a different trailer...easyist way to see if it is a controller issue.

Did you check the emergency brake pull away?

You are definately sending 12V to your trailer brakes. You lost me on what plug you converted to. Can you post pics.

It is possible that it's the fault of the brake controller. Check the blue wire at the brake controller for power with the trailer connected. If it reads 12V then you have a bad controller. The voyager is inertia activated so if it's mounted vertical and you have 12V to the red (signal) wire then it will do the same thing.

What I think is going on is you have the 12V wire hooked to the trailer brake circuit on the trailer.

my trailer plug is the 7 flat RV style now,


my voyager is mounted parallel to the floor ON the floor

Is this the plug you have? If so this is how it should be wired, but ignore the wire color just incase they didn't use standard wiring color:
Attachment 229405
Time to bust out the test light and find out why you are getting power to the electric brakes. Double check that you don't have 12V and electric brakes switched or that the connections aren't shorted to each other. I have seen the set screws for the wires come out and short connections in the plug.

ill have to use my voltmeter as my test light is in pieces.
how do i check them? engine running? parking lights on? key on engine off?

I'd start with everything off. If you don't have power to the brake wire then start turning on things like parking lights, or ignition. That will help you trace the short. If you still have constant power there remove the brake controller from the equation by unplugging it (depending on the age of the voyager) or cutting the blue (output) wire. Go ahead and disassemble the two 7 way connectors, check for shorts or switched wires, and good luck.

That trailer prob REQUIRES you have a battery installed. Beg, borrow or steal one while you try to figure out this problem. Reread post 17.

OR: The Voyager isn't mounted as it should be..... If it's laying on the truck floor, the inertia switch is preventing it from working right.

update:

bought a new test light. with key on,parking lights on, i have power to lower left and upper right, respectfully electric brake output and tail-lights....

DOH,

will cut blue wire and see if light goes out

You must have the aux wire from the truck going to the brakes on the trailer. I'd unplug your brake controller and see if it still does it.