I recently bought a 2005 F-150 Lariat Supercrew and I'm trying to figure out the trailer wiring for this thing. It came with the factory installed "trailer tow package." To start, my bass boat trailer comes equipped with surge brakes and has a 5 pin flat wiring connection. Now, to state the obvious, the F-150 with the tow package comes equipped with a 4 pin (flat) and a 7 pin (round) wirirng harness. So my question is does Ford itself have an adapter that would go from my trailers 5 pin flat to the Ford installed 7 pin round, and if so does anyone know the part #. (I could sware that my '99 Expy that I had a few years ago came with this adapter) I went to my local Ford dealer for this part and they seemed to know what I was talking about but in the end they just order me a the 7 pin wiring harness.

Also, because the trailer has surge brakes the only thing I need to do is install the circuit under the hood, correct? I don't need to install the brake control adapter under the steering wheel. Is that right?

Thanks for any help in advance.

 

Does your trailer have separate brake and turn signal lights? This would be the only reason for a trailer to have a 5 pin wire connector. Looks like you might need to convert the trailer lights to standard trailer lights (turn signal and brake lights are the same bulb/ wire).

 

Hello N901 and welcome to the club. You will not need a brake controller with surge brakes. The relay for the power wire to trailer goes in the empty spot right in the middle of the fuse box. Its behind the passenger kick panel by the way not under the hood. Sounds like Rocky is correct, if you cant find an adapter at a boat dealer you may have to convert trailer to 4 pin connection. Good luck and good boating!

 

I'll bet the '5th' wire is for the reverse light switch that will disengage the surge brake function while backing up on the trailer. You don't need a separate 'brake controller'.

On the 7 pin connector, the reverse wire is the center pin. You will also need a relay under the hood. The excact location escapes me, and since it's a '05, it's probably not even close to my '97.... But, I'm pretty sure it still needs a relay.

I've got an adapter that fits into the 7 pin to make a flat 4, so I'm sure they have one for a flat 5 as well. You just have to make sure the 5th pin is for the reverse light and that it's wired to the center pin.

Good luck!

Mitch

 

Anyone.

I have a 2010 f150 and when backing up with my boat the trailer brakes will not release. I tried this with another truck (GMC) and have no issue. It worked before but after 6 months it fails to activate the bypass solenoid on my trailer. I took it to Ford in Naperville, IL and the too could not figure out the cause and seem to love to blame it on the trailer. I took my buddies GMC to ford with my boat and even when I showed them it worked with that truck they continue to blame the trailer. We plugged it into another ford truck on the lot and had the same issue. So the service writer at Ford said it must be my trailer even tho it works on the GMC. I was there for 4 hours with my buddy, my boat, and the service writer and his mechanic's. Finally they bypassed the plug and connected my trailer straight to the battery and woola, it worked.

Anyone else have this issue with their ford? And if so what did you do to resolve it? I'm thinking that there is a bad ground wire to the 7 pin plug. This is all standard Ford and no aftermarket components.

As of now Ford is going to replace the 7 pin plug and reground the ground wire from the frame. But still unsure if they can resolve it. And the service writer is still unsure if its a trailer issue which makes me want to punch him in the face. But I wont.

Help if you can and thanks for reading this long winded thread

JP

 

I would get an adapter like this one and call it a day.

 

Thanks for the replay, although that is the connector I have. Just so you all know, ford does have an issue with their 7 pin trailer connectors and grounds. After they installed a new one and re-grounded it in a better location I was able to meter out the correct voltage. But unfortunately my trailer still didn't work when I picked it up. Believe it or not, I left my boat and trailer at ford while they were trying to figure this out and they shorted out the solenoid in my trailer by jumping around circuits (ON MY TRAILER) without having a clue on what they were doing. When I picked up my truck and trailer with the GMC I tested it on earlier, it no longer worked either. I now have to replace the solenoid for my surge brakes in my trailer. WTF???? but at least I know that even new fords have this same issue.
If any of you experience this, make sure you have at least 12vdc to the back up lamps and ground. If you do not check your ground, clean it up and re-ground it. This should solve the problem and I should of just did it myself.

JP

 

Hi looking for a little help 97 f150 5.4 4x4 electric trailer brake flat 4 pin connector 6? 7? 8? pin round connector (6 around the outside 2 prongs in the middle) only 4 prongs do anything the rest blank - newer body style installing third brake light on my shell (fail) long story worked fine till i shorted it to the shell found the 20 amp under the hood turn and parking work to the plug again brake does not Checked every fuse in 3 boxes under hood every fuse under driver side dash ohm metered every relay from all where is the fuse or relay i blew up AHH
Thanks
John