Flatdaddy

I tryed to tow with my 2009 SC last weekend and when I hooked the trailer lights to the truck, no lights. So I got the test light out and not surprisingly there was no power to the taillight plug. So its off to the dealership on Sat. to see why. I'm not very happy because I bought this truck with a tow packcge and I figured it would have working taillight plug, Apparently the prep guy failed to check this. What a bunch of idiots! Well I'll keep y'all posted about my trip to the stealership, OOPS! I mean dealership.

Hiddenmickey

You probably need to install the relays under the hood. I got the relays in a little plastic bag in the glove box when I took delivery of the truck. I think it may be discussed in the owners manual.

icantdrive55

Not sure if this is correct, but when I installed an aftermarket trailer brake controller in my '09, there was a package in the glove compartment with a couple of fuses that needed to be installed in the fuse block on the front of the radiator under the hood. Can't remember the number(s) of the fuse socket, but there should be an instruction page with your fuses. I also seem to recall that the fuses ONLY activated the hot wire to the center pin in the 7-way for charging on-board trailer batteries and other 12v hot wire accesories in the trailer, so maybe this won't help your problem.

Also, see the link below to another thread on this forum about a Ford TSB on the trailer wiring harness: https://www.f150forum.com/f38/traile...message-42598/

ji603

Ahhh so thats what that is.. I too have a small bag in the glove box with a 3 prong type fuse. Wonder why they dont install it before delivery

Hiddenmickey

The last three trucks I had came without the relays and fuses installed. Each time I asked the dealer to install them and they did without question. I still don't know why they just don't do it automatically. In fact, when I picked up the last truck, the salesman pulled out the bag and said "just let us know and we will install these for you." I said "how about now?"

ji603

Yup, keep us posted. From what I could find out, the relays/fuse in the packet only activate the trailer charge/power line.

The lights should still work regardless. I wonder if the trailer is wired properly or if one of the fuses blew in transit?

BlueSpark

Reviving this thread, I have the same problem (no power to trailer, fuses in the bag from the stealer). Fuse boxes all appear to be correct. Where do these fuses go? I don't want to visit the dealer on a Saturday.

BlueSpark

Found them. 9 and 21. Labeled "TT Battery Charger Relay" and "TT Battery Charge Relay Power", respectively.