Recently converted my '99 F-150 XLT Flare from 4-pin to 7-pin. I was a little pressed for time, and possibly too cheap, to buy the actual converter from the rear Ford 7-pin connector to go to my after-market Hoppy 7-pin receiver. Following their instructions, I connected 4-pin to 4-pin, reconnected ground, connected blue electric break wire, and orange wire (back up lights which I don't have on my trailer). I then tried to connect the black wire to the black wire from Ford. When I did this, I lost the taillights on the truck. So, I reconnected the black to what it was, and went about my day. Now trying to figure out how to get the Battery Charge connected. What did I do wrong? Do I need to splice into the Ford black wire? I severed and bypassed. Anyone's help would be greatly appreciated. I am trying to avoid the re-wire to Factory settings and purchase of another adaptor just to connect one lousy wire...

 

Huh? Orange wire is 12v positive auxillery charge.
Brown with a green trace is reverse lights.

Huh? There shouldn't be a black wire on the Ford side of the harness...the ground wire should be white and a pretty large wire compared to the rest of the wires used in the trailer wiring plug.

Here's the wiring break-down by color:
Running Lights.............Brown w/ white trace
Aux 12v Positive..........Orange
Right Turn/Brake..........Green
Electric Brake..............Blue
Ground.......................White
Left Turn/Brake............Yellow
Reverse......................Brown w/ green trace

For position of said wires looking at a 7 pin truck connector from where you plug it in (Where the trailer is plugged in).
11 o'clock....running lights
1 0'clock.....aux 12v positive
3 o'clock.....right turn/brake
5 o'clock.....electric trailer brakes
7 o'clock.....ground
9 o'clock.....left turn/brakes
center........reverse

 

Thanks for the info. I figured it was something simple. I followed the directions included in the 7-pin and it just wasn't right. Don't need the back-up lights anyway...

Great help - and led me to this forum, which is awesome!

 

I bought this truck used without an owner's manual. The R/L turn signals don't work on the trailer harness and I'm pretty sure it's the relays under the hood but have no idea which ones.....any help would be appreciated....