I am looking for a wiring diagram or a list of what pins need to be connected to what to make an adapter to go from 7 round on a big truck to 7 blade RV style on a trailer.

 

Is this what you need?

http://www.etrailer.com/faq_wiring.aspx

 

J27-J29.pdf

Scroll down to find the 7 round pin connector

 

That PDF helps. Next question: semi style has seperate stop and turn. How do I combine those into one? Directly splicing them isn't going to work. That would trigger flashing lights on all 4 corners of everything....

 

That is controlled by an in cab module. Are you hooking a tractor to a camper? what is you main objective?

This is the breakdown for all class 8 tractor plug configs.

White- ground
Red- brake light
Brown- marker lights
black- marker lights-(usually upper clearance)
Yellow- left turn
Green- right turn
Blue- auxiliary center pin


Tim

 

Tim, yes, thats essentially what I am trying to accomplish. I have combined stop/tail/turn lights on the trailer instead of separate turn and stop.

 

if you were to tap into the tractors brake lights instead of the tractors trailer harness it would save some time you could just put a rv plug on the tractor. Most tractor lights are setup already with the stop and turn signals combined. I don't know if you would be interested in that but it is a easy method. You can tap in just before the tractors tail lights or run an all new line back from the firewall. Just an option.

 

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This is good advice, it is also what I have done with one of our tractors that we use for hauling campers as well. The only thing you would have to add is the battery charge wire, and the electric brake actuation wiring (if you want). You can just leave the plug coiled up and tucked into the inside frame rail when not in use. It works very well for us.


Tim