Trailer Wiring
Logistics Pro
Joined: Mar 2002
Posts: 3,881
Likes: 84
From: Wake Forest, NC
Trailer Wiring
For anyone interested, here is what I found about adding the 7 pin wiring to my 2000 f150 7700.
From what I can tell, all f-150's are prewired for all the trailer wiring. Its best to use the factory wiring method as you get the benefit of fused trailer circuits and relays for the backup lights and charging circuit for trailer batteries etc as well as prewired trailer brake controller connector.
Under the back of the truck, on the frame, is the main wiring harness. On my truck, i had a 4 pin trailer adapter and an aftermarket hitch. The 4 pin harness goes between the main harness and the rear lighting harness. You have to replace this harness with the ford 7 pin harness to get the 7 pin adapter. It took some time to figure out what part I needed, as the dealers must not get this question very often. No one was able to tell me for sure what I needed and all of them wanted to order it. Finally, I got one guy at the dealer I normally deal with who got it exactly right. I was surprised to see it came with a 4 pin and 7 pin wired in, no adapter needed if I wanted to tow a light trailer. Installation was easy, except I had to rebend the bracket for the plug because I didn't have the ford reciever hitch. The plug is designed to bolt to the hitch, not the bumper.
I also had the plug under the dash for when I want to install the brake controller. I will need the extra relays, but those are for trailer power and backup lights, so if I don't need those I won't have to buy the kit.
The dual Ford 7/4 pin adapter harness only cost me 39.00, retail list at 49.00. Not bad for a secure weatherpack install. You can get 7/4 pin universal adapters for $25.00 but then you have to cut and splice. The brake controller install kit with the relays is $18.00. Not sure if thats really worth $18.00 for a pigtail and two relays though.
Chris
From what I can tell, all f-150's are prewired for all the trailer wiring. Its best to use the factory wiring method as you get the benefit of fused trailer circuits and relays for the backup lights and charging circuit for trailer batteries etc as well as prewired trailer brake controller connector.
Under the back of the truck, on the frame, is the main wiring harness. On my truck, i had a 4 pin trailer adapter and an aftermarket hitch. The 4 pin harness goes between the main harness and the rear lighting harness. You have to replace this harness with the ford 7 pin harness to get the 7 pin adapter. It took some time to figure out what part I needed, as the dealers must not get this question very often. No one was able to tell me for sure what I needed and all of them wanted to order it. Finally, I got one guy at the dealer I normally deal with who got it exactly right. I was surprised to see it came with a 4 pin and 7 pin wired in, no adapter needed if I wanted to tow a light trailer. Installation was easy, except I had to rebend the bracket for the plug because I didn't have the ford reciever hitch. The plug is designed to bolt to the hitch, not the bumper.
I also had the plug under the dash for when I want to install the brake controller. I will need the extra relays, but those are for trailer power and backup lights, so if I don't need those I won't have to buy the kit.
The dual Ford 7/4 pin adapter harness only cost me 39.00, retail list at 49.00. Not bad for a secure weatherpack install. You can get 7/4 pin universal adapters for $25.00 but then you have to cut and splice. The brake controller install kit with the relays is $18.00. Not sure if thats really worth $18.00 for a pigtail and two relays though.
Chris
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Joined: Sep 2001
Posts: 30,255
Likes: 37
Trailer Wiring
>The brake controller
>install kit with the relays is $18.00. Not sure if thats
>really worth $18.00 for a pigtail and two relays though.
If it comes with relay sockets all wired up it probably is worth it.
Thanks for the info!
Thanks for using FTE!
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>install kit with the relays is $18.00. Not sure if thats
>really worth $18.00 for a pigtail and two relays though.
If it comes with relay sockets all wired up it probably is worth it.
Thanks for the info!
Thanks for using FTE!
[font color=red]As a Moderator I do not "Subscribe" to most topics,
please send email/pm if you need a reply -Thanks![/font]
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Logistics Pro
Joined: Mar 2002
Posts: 3,881
Likes: 84
From: Wake Forest, NC
Trailer Wiring
Its a 4 wire plug pigtail (B+ input, brake signal, trailer output signal, and ground I think), and two relays to put in the main fuse box.
I figure the relays are a couple of bucks but I could be wrong. Its only worth it if you need them for trailer power and backup I suppose.
Chris
I figure the relays are a couple of bucks but I could be wrong. Its only worth it if you need them for trailer power and backup I suppose.
Chris
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