Q Re Proper hookup of 7 pin connector

[EmeraldCityGuy]

Yesterday I installed a 7 pin trailer connector to my 92 K2500. It appears the original came with a 4-pin. It's a Camper Special and I'm not sure where the connector would be for hooking that up - the manual says it's up front in the bed. Since there is a plastic bed liner, I haven't looked for it except underneath (and could not see it). In hooking up the 7-pin, there is a blade for 12v power and the center pin for Auxiliary Power. Should both or either one be hooked up to constant 12v power, or should both be switched? I'm guessing the trailer brake back-up battery charging circuit is powered by the 12v blade and the 12v interior lights are powered by the center Aux Power. Is that correct?

Appreciate the help.

Rich
Maple Valley, WA

 

[GoToGuy]

Don't guess with electricity. What electric diagrams are using? Have looked in the 92 service manual you can get in the forum for free download. Section 8 has all diagrams for all available circuits, and locations. Does your brake manufacturer have the recommended wiring hookup?
On my 86 K3500, the accessory circuit was used for switched lighting inside a two horse trailer with forward changing room.

 

[JOHNGAAA1]

There is an adapter for a 4 pin to 7 pin. No cutting and simple. The 4 pin connector is on the left rear side attached to the tail light harness.

 

[EmeraldCityGuy]

Don't guess with electricity. What electric diagrams are using? Have looked in the 92 service manual you can get in the forum for free download. Section 8 has all diagrams for all available circuits, and locations. Does your brake manufacturer have the recommended wiring hookup?
On my 86 K3500, the accessory circuit was used for switched lighting inside a two horse trailer with forward changing room.

GoToGuy - I bought a Cut kit 7-pin to 4-pin connector. The wiring diagram says "12v power" and "Aux Power". It says no more. There are red LED lights on the outside of the 7-pin connector (that is supposed to let you know if you have a good connection with the trailer, I believe). Those two pins illuminate their respective LED lights as soon as I hooked up the wires to constant 12v power. I understand the 12v power that may go to the trailer battery should be hooked up to 12v switched power, but the Aux Power, I was thinking controlled the interior lights in the trailer - and I thought that should have power all the time (there is a on/off switch inside the trailer of the overhead lights).

 

[EmeraldCityGuy]

There is an adapter for a 4 pin to 7 pin. No cutting and simple. The 4 pin connector is on the left rear side attached to the tail light harness.

Yes, John, it was relative simple to hook up the connectors, but there were FOUR additional wires to the 4-pin connector. Those contain the 12v power and Aux Power. Just trying to figure out where those should be hooked up to. The few sources I consulted online did not specify constant or switched. Rather than waste more time in that search, I thought of posting the question here.

 

[GoToGuy]

Are you wiring for the truck for pulling a light weight utility trailer, no brakes? Or is this to pull an RV type trailer? Trailer have brakes, electric or hydraulic?
The camper wire bundle splits off of the main loom just behind left side of cab, would have taped together and stuffed in left forward stake pocket on bed. I would just lay down under cab bed space and look for small bundle going up, or in that area.
The adapter is fine the drawback is, it presumes you have a plan or knowledge of wiring vehicles.
Are you using this plug with your trailer? Is your trailer plug wired to RV manufacturers standard plug wiring practice?
Fancy plugs are great, but what is your objective?
You don't have to use all the plugs circuits if don't have a need. "I can't tell how to get there if I don't know where your going."

 

[packer0440]

Aux power could be anything, reverse, switched, etc. If the trailers you will be towing don't have any special accessories, it may not even be necessary to hook this up (as GoTo said). The 12v power one I think is always hooked up exactly like it seems it would; 12v constant power (with a fuse).

 

[HotWheelsBurban]

I think the 12V aux circuit is for electric brakes, power jacks, that kind of thing. I could be wrong though....

 

[Nad_Yvalhosert]

All the 7-wire connectors I install get "Reverse" in the center, 12V direct power to the "top-right" (as you look at the truck side connector)

 

[Frank Enstein]

I found these. I hope they help.

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