SpeedViktm

1. Yes, it's been activated by a dealer.
2. Yes, it looks like all of the fuses & relays are in place.

2013 STX SCab. Did not come from the factory with the tow package. I added the TBC, changed the 7-to-4 pin pigtail at the back to the 7-to-7 pigtail. Connected the 4/7-pin socket/bracket combo for the F250 as recommended by Tasca.

Lights all work, but the trailer brake does not appear to be based on the reading here. Manual control says "Trailer Disconnected" and the gain adjust changes but says "No Trailer Connected". My understanding is that if you see that, the brakes are not working. A test light on the brake output at the socket did not light up, but I know that's not a good simulation of a trailer being attached. I did not have an opportunity to actually try applying the manual brake at low speed to see if they worked, no where to do it. The trailer is brand new, unlikely it has a wiring problem. No impossible, just unlikely.

Did I miss something, or am I one of the lucky ones who's truck just won't accept the TBC being installed afterwards?

EDIT: Solution down in post 30...

techrep

iTrader: (1)

Hook the trailer to somebody else truck to verify

Ricktwuhk

The true way to test this is to sit in the parking lot, apply full trailer brake, and step on the gas. You should see the trailer tires not turning.

If it doesn't work, then either #1, #2, or your wiring is at fault.

smokeywren

If you don't have the trailer tow pkg, then your plug at the back of the truck is not properly wired to connect a trailer brake controller. Simply changing the 4-way plug to the 7-way plug is not good enough. Automotive wiring is not my thing, so I would take it to a Ford dealer or RV dealer and have them wire the 7-pin plug to the fuse box/power distribution box so all 7 pins work as designed, including the trailer brake controller wire under the dash.


Probably your trailer brake wire is there, but you don't have it properly connected to the fuse box with a relay and fuse. On my F-150 with the tow pkg, the dealer had to add the fuse and relay to activate the trailer brake wire under the dash.

SpeedViktm

The main wiring harness at the back is 7-pin, it had a 7-to-4 pin adapter/pigtail that reduced it down for the stock 4-pin that came on the truck.


I looked thru the owners manual and checked all of the fuses and relays that had anything to do with a trailer and they all appear to be there and are the proper ratings.

EventHorizon

Incorrect.


On my truck it came with only a 4 pin connector and no hitch. Obviously no tow package either.


I installed the TBC and the Ford 4/7 plug that connects above the spare tire (the flat 4 pin was connected here, remove that). I went with the Ford 4/7 plug to try to maintain as much OEM as I could to insure compatibility.


Dealer flash for the TBC to work and I'm all good.

smokeywren

Yeah, OP didn't mention having the dealer flash the PCM. Without that flash (update to the computer) the ITBC is not going to work.

doctorschlachter

His original post suggests he had it flashed.

SpeedViktm

Um yeah, that's kinda the very first thing I said..... Anyhow.....

I have positively confirmed the TBC isn't working.

1. Used a clamp to hold the manual control closed, lifted trailer with a jack, wheels spun.
2. Wrangled up a guy nearby with a new Dodge truck with factory TBC, his truck showed a trailer connected and I could hear the trailer brakes engage. Off to buy a new Dodge....OK, not really.

My trip this weekend isn't mission critical and I can delay it, so I think I'll go back to the dealer and have them see what's up. It also doesn't look like the 12V is working either, lights inside the trailer don't work.

Steve Osborne

check for power at the trailer plug on the truck...have someone apply brakes or manually using the tbc unit.....no power?...then check for the fuses and relays....hope the brake wire is in the harness....next the 12v charge same idea...test at the plug.....only works with truck running---works off a fuse and a relay as well....

adding....charge circuit....relay 9 fuse 21 30 amp and tbc 17- 30 amp fuse under hood fuse box..
the inside panel .. fuse 37 for tbc 10 amp...
http://www.fordservicecontent.com/Fo.../13f12om3e.pdf