Hi, I am new to VTT as I just bought myself a 1966 Kit Companion. It is in pretty good shape but I am going to do the requisite renovations to get it to be road worthy and safe. One of those things in reverting the tow wiring back to 7-pin from 4-pin downgrade, which I don't know anything about. Further, the color of wires seems inconsistent with the advice I have seen on VTT.
So, coming from the trailer I have 7 wires. Two brown, two red, green, yellow, and a thick black one. Then, at the hitch where they spliced to the 4-pin, the wires are green, brown, yellow and white.
I am going to end up testing them to see what's what but I wanted to just ask here in case anyone had insight. Thank you.
Since you have the 4 way hopefully still connected, it makes your job easier. Brown would be Tails and Marker (clearance) lights. Trace the brown back to whatever trailer wire it is connected to and label that wire "TM" or TAILS. Do the same with the yellow (LT) and green (RT). These wires are following the 4 way trailer wiring code.
White is ground, which is easy. I would install a new ground bolt to make sure it's secure and clean. You should be able to find the trailer ground by tracing the wires and see which is bolted to the frame.
You now know which wires are tow wiring and all are labeled. NOTE: some trailers have 2 wires running the tails and clearance lights. (maybe the two red wires?) If everything is working, not a worry.
I'm guessing the thick black wire is your hot 12 volt into the trailer. Look at your brakes and see what 2 wires are connected to them. Most are in a sheath cover the two.
I won't get into this now, but you will be changing from the 4 way color code to the 7 way. More later.
Hope this helps and hope the 4 way was still connected. Let us know how you do.
I am hitting a snag. I got the 7-pin junction box all wired up. I still need to install the 7-pin on my truck but that's another matter. I have been testing the electric current with a 12 volt battery gator clipping to the ground and then to the post I want to test. It has been going gangbusters. But, today, I wanted to reinstall my running lights after having cleaned the rusted plates in vinegar and getting new lens. I tested the wires one last time to make sure the current was running through and it was, pre-install. But, then I re-installed the running lights and nothing worked. I then uninstalled everything and tested the bare running light wires with a multimeter with the battery hooked up and nothing. I am not sure what went wrong.
Side note, is there any VTTers in Sesttle area that would be interested in walking me through this in-person?
If nothing works, it's usually the ground/grounds.
Ground the skins to the frame. You can use a small short wire with ring terminals on either end; one bolts to the frame, the other to a screw on the skin. Place the screw where the skin folds under the trailer. Ground both sides and front and rear skins this way. NOTE: skins make very poor grounds. It's best to run a ground wire to each light when you rebuild the trailer.
When testing with the battery, be SURE the ground lead is firmly clamped to the frame. Also triple check the trailer grounds; that they are clean and secure. When in doubt ground it again.
PM me for my email if you need to. I'm North of Seattle but can't really travel right now because of a bad leg break.