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DougE's avatar
DougE
Explorer
Feb 20, 2017

Tow Vehicle 7-Way Plug Emulator

This was my rainy day project. Build a test unit to replicate the trailer plug on my tow vehicle. I can insert the 7-way from my trailer, hook up a battery or charger to the side posts and check each of the trailer circuits. Everything was pretty much available at Home Depot.

29 Replies

  • BB_TX wrote:
    Aww, come on. After all that work you used a permanent marker to label the switches? :B


    Well if we're going to be picky why when we're looking at the labels right side up is R-Turn on the left and L-Turn on the right? :W
  • Aww, come on. After all that work you used a permanent marker to label the switches? :B
  • Now that is just a thing of beauty.
    I like how you broke apart the individual circuits and used a good switch to interrupt. Do you have any pictures of the innards so we can oooh and ahhh over your wiring skills?
  • RoyB's avatar
    RoyB
    Explorer II
    Pretty handy.... I already am using one of those 7-way testers that plugs into the truck side and has small led's to show what the truck is doing... Always lets me know if the I am having wiring problems on the truck side or the trailer side...



    I have all of my 7-way connections on the trailer side in an electrical box mounted on the inside of the trailer frame and was always going to run a couple of wires from the 12V and Trailer Running lights to a wall switch mounted on the wall near the entrance door to turn on my running lights for emergencies to let Rescue Squad or Police know which trailer I was in at the campground when needed...

    Your box would be very handy to trace down trailer safety lights problems...

    Roy Ken
  • DougE wrote:
    You're correct. Thank you spell checker.


    Hey, what do I know :W ... maybe in Texas it is "immulator". :p
  • I've got one of those. It will check the lights but also will cook, clean, do the dishes, and laundry.