6 Pin Vs 7 Pin?

[uchi]

i did some reading on installing a brake controller and some of the info i came across was saying that some gm connectors are wired for a 6 pin and some for a 7 pin. what is the 7th wire for? and also is it the same connecter for a 6 and 7 pin or if i want to use a 7 pin do i need another complete connector back there?

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Truck comes stock with a 7 pin. 7th pin should be either for backup lights or trailer brakes.

[uchi]

ok perfect, it must have been an old article i saw for an older gm truck or something. thanks bud, one more thing, i see alot of enclosed trailers have built in interior lights, does the 7 pin have a wire in it that powers something like that or a small winch even or is that something that needs to be run seperatly?

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Yes the 7-pin has a constant 12v supply in it. You just have to add a fuse under the hood to make it give 12v. That 6pin you're talking about lokks totally different and is obsolete now.

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Here's a 7-pin to 6-pin adapter. Just to show what 6-pin looks like.

 

[uchi]

oh ok i was always under the assumptoin it was the same basic thing with just 1 pin not hooked up, thanks for the help guys

[c4cruiser]

This is a 7-pin trailer side connector:

 

This is the truck side:

 

The 7-pin connector is very common for "RV" use like pulling travel trailers or car trailers. Notice that the connector uses blade-style connectors rather than round pins. With this type of connector, you can get adapters for light trailer wiring which is the flat 4-pin connector.

 

If your truck has the towing package, you will have the 7-pin connector next to the receiver. To power the 12v accessory wire, you need to add the 40A fuse in the underhood electrical center (I mentioned this in your trailer brake controller thread). If the truck does not have a towing package, you may have to run wires back to the rear bumper or add the necessary harness.

 

The 12v pin needs to be powered up if you tow a trailer with electric brakes and the trailer has a "breakaway box". This is an emergency braking system for the trailer if it becomes disconnected from the truck. The trailer will have a small 12v battery that energizes the brakes so it will stop by itself. The 12v pin keeps the battery charged. And the pin will also supply accessory power to a trailer for interior lights. The 12v is always on.

 

I don't think that pin will have enough amperage to power a winch. It would be best to run heavy wire (4 gauge) from a dedicated battery to the winch. Or outfit the truck with a auxiliary (second) battery. Any RV place or trailer sales place can provide the necessary wiring and stuff to add one.