I have an 11 f150 with the oem brake controller. Trailer lights and brakes work. I have no power to the electric jack on the trailer. I did a search and found I had to install a fuse/relay in slots 9 and 21 in the fuse box. I checked and both are already in from the dealer. Am I missing something?

 

Are the batteries in the TT fully charged? Your brake controller has nothing to do with the operation of the electric jack..... only the lights, trailer brakes, and keeping the TT batteries topped off. I think that the TT jack still runs off the TT batteries even if hooked up to the truck.....
It sounds like you might have a wire loose somewhere for the jack itself....or the TT batteries are not charged up???

 

Yes you need a battery on the trailer the 12 volt feed from the truck is not enough to power it but will keep the trailer battery charged. Also the feed is only hot with the ignition on.

 

The trailer does not have a battery for the jack. Its a 24 ft cargo trailer, the only battery is for the brake system. That being for the break away cable. I work for a construction company and there chevy trucks are able to hook up to the trailer and use the electic jack. Any other ideas?

 

which color wire is the jack wired to on the trailer? it should be wired to the "black" on the trailer harness which is a straight power hookup. If that's the case, then the truck has to be in the "on" or "run" key position. if it's wired to brown, the load is probably too much for the truck and should be rewired on the trailer side to "black"

 

x2 on your 12V line to the trailer not being enough power for the jack. Trailer jacks should be connected to the trailer battery.

 

the black, AUX TT (straight run to the battery of the truck) will carry 50amps. TT jacks are nothing near that unless the jack is very underrated for the load and/or the trailer is rediculous in the tongue weight department.

 

I guess im used to using the company vehicle. I think they have a hot wire directly to the battery going to the trailer plug. Im used to backing up, turning the truck off and hooking up the trailer. I'd be willing to bet if i leave the truck running and or leave the key in the forward position it would have worked.. Should have known better.. Thanks guys

 

correct, all other truck manufactures have a 12v hot lead in the rear harness even with key off/out. ford does not, so that could be your problem. glad we could help

 

I posted this in another thread, then came across this one.

I have a '11 FX4 with the stock trailer brake controller. Everything is getting power to the harness EXCEPT the 12v power pin. I think it's number 4 on the plug. I checked both the fuse under the hood, number 17 I think and the fuse in the passenger footwell, and it is ok too. Without the power the trailer brakes won't work. It recognizes the trailer and I can set up the gain, but no power.
Any ideas?

And yes, I tried it with the truck on.