Trailer Lighting/Wiring Kit for Snowmobile Trailer

Question:

I have a snowmobile trailer with a white wire a yellow and brown combination wire and a green and brown combination wire. I have a 4 pronged connection to the pickup with a green,white, yellow, and brown wire how do I connect them.

asked by: Vern S

Helpful Expert Reply:

Standard 4-pole trailer wiring uses flat-style connectors, like part # W787268 which is a trailer-side connector and part # HM48044 which is the mating vehicle side connector. On these items and on the 16-gauge bonded 4-pole wire # 16-4B-1 you referenced in your question the usual pin/function assignments are the same. These are as shown in the linked photo and in the article on trailer wiring that is included for you.

The one pin that is not like the others will be the GROUND pin which normally connects to a WHITE wire. The next pin over is for the RUNNING LIGHTS which are normally carried on a BROWN wire. The two remaining pins are for the YELLOW and GREEN wires; the yellow wire carries combined STOP and TURN signals for the LEFT side of the trailer and the green does the same for the RIGHT side.

It sounds like your snowmobile trailer may have had a "wishbone-style" harness with TWO running light wires and that it is now missing two wires, the left stop/turn YELLOW wire and the right stop/turn GREEN wire. Part # 002220 is one of these "wishbone" style trailer connectors. You can see that it has dual brown running light wires to make light hookup a little bit easier; there is a running light wire for each side of the trailer just for convenience.

You probably just need to replace the trailer side wiring harness so that you again have all needed circuits for all the trailer's lights (again, there are three circuits plus ground). It is often easiest to use a complete trailer lighting/wiring kit like # TL5RK which includes lights, wiring, reflectors, quick-splice connectors and even a license plate mount.