6-Pin to 7-Pin Adapter Questions

[MikeNNRV]

Taking over repair, maintenance, and probably use of Dad's f250 Super Duty.  Has three trailer connections; 1 4-pin flat and 2 6-pin rounds (one in the bed for gooseneck horse trailer and one at bumper for utility trailer).
I see on etrailer the adapter that will allow use of my 7-pin RV connector.

Is there any loss of function when using this adapter?  I read in other threads that these adapters can be easily customized but that would probably lead to other questions.

Any pin out testing I should do before buying one?  I assumed my rv connector was built to a standard.

 

[John From Detroit]

One of the things you need to know is the pin-definitionos on the connectors

4 and 7 pin are fairly common and the pins are (IN no particular order save 4 first)
Right turn/stop
Left turn/Stop
Tail
Ground
And on the 7 pin 
Brakes
Battery
Aux

6 pin may be the same but no AUX or no Ground.

Or .. Well my six pins are the first 4 (Those are common to all)
Pump and Pressure Sense  for my lube pump

(I drive a class A towing a car with a transmission lube pump)

So you need to make sure the pins have the same meaning.

 

[Isaac-1]

Be aware there are 2 different wiring standards used on 6 pins so you need to know which one your trailer uses, if you plug a 6 pin trailer into the tow vehicle.      Some of the 7 blade (tow side) to 6 pin (trailer side) adapters have an easy to switch wire that lets you convert between the two wiring schemes.

 

[NY_Dutch]

The 7-pin round connector has a separate brake light connection where the 6-pin round combines the turn and brake light connections.

 

[Gary RV_Wizard]

The 7-pin round connector has a separate brake light connection...

The one in that attachment does, but most do not. The usual 7-pin has a combined stop & turn, as do most trailer wiring harnesses.  You find the alternate pin-out with separate brake pin on tow vehicles that have separate stop lights. I think you will find the one I've attached to be more common, on both tow vehicles and trailers.

 

[NY_Dutch]

The one in that attachment does, but most do not. The usual 7-pin has a combined stop & turn, as do most trailer wiring harnesses.  You find the alternate pin-out with separate brake pin on tow vehicles that have separate stop lights. I think you will find the one I've attached to be more common, on both tow vehicles and trailers.

I took the diagrams to show what he's working with, but yes, the more common 7-pin is a flat blade connector with combined stop and turn connections.

 

[Gary RV_Wizard]

I see on etrailer the adapter that will allow use of my 7-pin RV connector.

Is there any loss of function when using this adapter?

Well, obviously 7 pins is more than 6, so one pin isn't getting fed.      The extra pin on a 7-pin is an auxiliary that can be used for a variety of things, but the most common is probably a backing light.  If the trailer utilizes the 7th pin for that or anything else, it is "lost".

 

[Gary RV_Wizard]

I took the diagrams to show what he's working with, but yes, the more common 7-pin is a flat blade connector with combined stop and turn connections.

You may well be right, Dutch. His trailer is listed as a pop-up and they are often non-standard different when compared to larger RVs that use the bigger 7-pin. Which of course brings up the question of what sort of adapter he is looking at.

I assumed my rv connector was built to a standard.

It probably was, but it's "a" standard, not "the" standard. As can be seen, there is more than one.

There are also adapters available that enable a vehicle with combined stop/turn to mate with one that has separate stop lights.

 

[grashley]

It was my understanding that clearance lights were on the tail light circuit.  Also, many do not have a separate brake light, but this is combined with turn signals.

These two pins carry BRAKES and aux.
Somewhere, you MUST have wiring for trailer brakes!!!

Here is the e Trailer diagram for 6 and 7 pin wiring.    https://www.etrailer.com/faq-wiring.aspx