Pin out for 7 pin Pollack connector

[theoldwizard1]

I have a 2012 Expedition EL that I need to install a 7 blade Pollack connector on (it only has a 4 pin connector). I have trailer brake controller wiring kit (7L1T 15A416 AA) from another vehicle. It shows that the center pin is for reverse/back up lights (wire color code gray-brown) and the top right (looking into the vehicle connector) is +12V (key on) auxiliary power.

I have seen other diagrams that have the center as auxiliary power and the top right a +12v, always hot.

Which wiring is more common on travel trailers (I have not seen many with reverse lights although it seems like a good idea).

Any opinions on "key on" power versus "always hot" power ?

[Ozlander]

There is only one standard for 7 pin flat blade connectors.

[theoldwizard1]

Bob Landry wrote:
Don't try to turn this into rocket science. The Pollak connector has the terminals marked with the correct wire color. If your existing wiring from the vehicle is missing some colors, you are going to have to provide them. All travel trailers 7 way plugs are wired the same and you are going to run into some issues if you try to roll your own.

I am NOT trying to "roll my own" (other than the +12V "key on" vs. "alwyas hot"). I just want to know for certain what is "standard".

It also seems odd to my that there is a pin for reverse/backup lights when few TT actually have them.

[Bob_Landry]

Don't try to turn this into rocket science. The Pollak connector has the terminals marked with the correct wire color. If your existing wiring from the vehicle is missing some colors, you are going to have to provide them. All travel trailers 7 way plugs are wired the same and you are going to run into some issues if you try to roll your own.
I just had to replace the plug on my Outback. The plug was such a sloppy fit with my trailer brakes stopped working altogether. The Pollak plug literally snaps in place, and I had read somewhere that Ford and maybe the other truck makers use Pollak outlets. The one on my trailer was a Bargman, FWIW.

[theoldwizard1]

Pathfinder75 wrote:
etrailer.com is a good source for trailer tow information including wiring. SEE: http://www.etrailer.com/faq-wiring.aspx This shows the popular 7-pin flat terminal and other plug setups with proper positions for circuits.

etrailer.com's diagram for the 7 blade Pollack connector matches the Ford diagram.

I might make a jumper to replace the "auxiliary power" relay so I have the option of it being "key on power" or "hot at all times".

The relays and fuses are all installed, so I wonder if there is a pigtail coming out of the fuse box (under the hood) and where does it end (it obviously NOT go all the way to the back) ?

[Pathfinder75]

etrailer.com is a good source for trailer tow information including wiring. SEE: http://www.etrailer.com/faq-wiring.aspx This shows the popular 7-pin flat terminal and other plug setups with proper positions for circuits.
I believe most are wired hot all the time. This would be popular for cargo trailers for dome lights. Just remember to unplug the trailer connector to prevent accidental draw on vehicle battery if parked several hours or days.

[Old-Biscuit]

I have only seen a +12V power on center on a 6 pin....not a 7 pin

The differences I have encountered on 7 pin is the positions on a 'flat blade' and a 'round pin' connectors.

Both have the +12V at the top right (1 o'clock) position & running lights at top left (11 O'clock) position
The other blades/pins are completely different

Turn lights are opposite positions
Brake controller and reverse lights are swapped
Grounds are opposite positions

As for key on vs always hot......I prefer HOT as I have other devices I plug into truck receptacle and don't like having to turn key on to use


ON EDIT: the 'auxiliary power' terminology seems to show up when looking at trailer vs vehicle connections......same as +12V power on vehicle side.