6 Pin 7 Pin

[macnkat]

My Bounder has both a 6 pin connector and a 7 pin connector which is great for all applications except my Stehl dolly which is a 4 pin.

I'm assuming it makes no difference on whether to use a 4-6 adapter or a 4-7 adapter...is that right?

[450Donn]

Should not. The 7th pin as I remember is for battery charge only.

[JMonroe]

I've never seen a 6 pin, but have used the 7 to 4 pin. They're pretty cheap.

[TXiceman]

Most auto or trailer shops will have a 7 pin to 4 pin adapter plug.
Amazon.com: Reese Towpower 74607 7-Way to 4-Way Flat Blade Wiring Adapter: Automotive

[RustyJC]

I'd go for a 7-to-4 adapter as the pin out convention on the 7-pin connector is much more consistent since it's used by vehicle and RV OEMs. That isn't the case, unfortunately, with the 6-pin connector where trailer brake and battery charge wires are frequently interchanged on the pin-outs - this manifests itself as locked trailer brakes when one attempts to pull out after hitching up. The problem is so prevalent that there are 7-to-6 adapters that have toggle switches to swap these wires internally!

I believe the "missing wire" in the 6-pin connector is the auxiliary center pin in the 7-pin Pollak connector that's normally used for back-up lights.

Rusty

[BigV]

Rusty is correct. The 7's have backup lights. It is also sometimes used to disengage a surge brake so you can back them up.

Either one will work. The adapters for 7->4 are much more common and relatively cheap.

[macnkat]

Thanks everyone...7 it is.

[wa8yxm]

The pins not in any particular order

Ground (the odd pin on the flat 4 is ground)
Tail/marker lights
Right stop/turn *
Left stop/turn *
Brakes
Battery charge **
Back up lights/aux **


* On a flat 4, the tail/marker is next to the ground, the right and leaft, I'm nto sure the order.

** I am not sure which of these is on the six pin, but the difference between a six and a seven is the other one.