Does every ford with a factory 7 pin connector have all 7 pins used? Is there supposed to be a +12v supply there to charge trailer batterys? Or did only some of the trucks get that?

 

The seven pin connector has pin assignments as follows.

1. Left turn signal
2. Ground
3. Electric trailer brakes
4. Right turn signal
5. Voltage in run (fused)
6. Trailer Tow relay, switched output
7. Trailer reverse lights.

Pin 5 is designed for the trailer battery charge. Pins count counter clockwise from the eleven o'clock position as pin 1.

 

The battery charge circuit has a fuse & relay under the hood.

 

Every 7 pin setup must have 12 volts to keep the trailer battery up to full charge because it is used solely for emergency trailer brake operation in event the trailer gets loose from the tow vehichle, trips/pulls the switch cable and automatically applies the trailer brakes.
If it's not there, you have a missing fuse/ relay or a specific issue.

 

You must have the relay and fuse installed to have 12v at the receptacle.

This is the standard for all trailer connections.
Trailer Wiring Diagrams | etrailer.com

 

That etrailer.com diagram is all wrong for a Ford (at least). Do not use it!

Here is the Ford diagram, taken from the 99 F150 EVTM:

 

Sorry but BOTH OF YOU ARE WRONG!!!! This IS the standard trailer plug wiring setup. Even FORD says so on the cover of my 7 plug on my Expy...

 

You're, kidding, right?

Nope, it appears I posted an "upstream" connector. Sorry about that. Good catch!

 

Yeah, I think the one you posted is the connector on the frame rail that the 7plug harness pig-tail plugs into. Also Shorebirds is for a 7 ROUND pin NOT the 7 flat, that is the most common plug. I think KingRanch used the same diagram you did. We never even answered the OPs question either... OP, MOST times only 6 pins are used, the 7th pin (center one) is usually not used, because REV lights are very rarely used on trailers. To get the rev. lights, batt chrg. (or12v+) and brakes to work you need to add fuses and relays under the hood and a brake controller inside . Even then the Batt chrg ONLY works with the key ON. To answer your question more thoroughly, YES ALL Fords use ALL 7 pins, it just depends if you add the fuse and relay under the hood for 12v+ at the plug.

 

I'm wondering how heavy the wire is for the battery charging pin on the connector.

I bought a small 12v winch from Harbor Freight with a hitch mount bracket, and it would be handy to be able to tie into the existing connector harness to wire it in.

I doubt, though, that the wiring is heavy enough.

 

Trick question? Yes, minitrk posted what's seen on my stock '98 F150. Of course some (now vintage) FORD trucks may have "a factory 7 pin connector" grafted on at some point to match a trailer plug, that hadn't been built w/the factory towing package that supports the standard 7 pin (6 flat pins w/center round pin) connector. I believe some basic F-Series trucks were only factory wired to support the simple, old fashioned 4 conductor trailer lighting & lack the extra wires running the length of the frame.

The towing package 12V supply is meant to charge trailer break away battery & is fused. If memory serves my '98 is designed for 30 amp fuse. This isn't nearly enough power to run most winches.

My reverse/backup light circuit was live as soon as I plugged in the 7 pin trailer connector pigtail to the tow package socket attached to the rear frame. No additional fuse or relay was needed. It apparently came from the factory or dealer with an adapter to run an old fashioned 4 pin trailer plug.

 

Running those small wenches require at least a 40 amp line.
Use #8 wire due to the length of the run.
As you load the wench motor heavier it will draw more current.
I ran a seperate line fused at the battery to a new seperate outlet at the rear bumper.
A small 4 pin connector with two each connected to each lead handles the current load.
I used it to pull a race car into the enclosed trailer when no help is around to do the loading.

 

my 12+v plug doesnt have any power. Dang. Well now comes the fun part of why.

 

Is the under hood fuse good?

 

havent checked it yet. Im not sure which one is the fuse, but know theres ar relay under there to.