4pin and 7pin trailer wiring, sanity check me!!

[USMCBuckWild]

Ladies and Gentlemen, I call upon you to sanity check my newest crackpot scheme.

I have a utility trailer that gets a decent amount of use between myself and my neighbors. It has LED lights throughout with reverse light capable tail lights, but the reverse wiring is not run since it is a 4 pin connector. Now, I like to be able to see when I back up and want to utilize the installed reverse lights. Just swap the connector for the 7pin, right? Not so simple. Majority of the neighbors (most are older) only have a 4 pin connector.

So, my plan is to purchase one of these:

https://www.amazon.com/Lavolta-Trai...078079&sr=8-2&keywords=7+pin+trailer+junction

Install it and run the stock 4 pin connector to the appropriate pins. Now I understand wiring like this will backfeed the 7pin plug, and that should not be an issue as it will be properly capped to avoid any shorting. This will leave me with a 7 pin with active reverse lights for those who have that plug as well as a 4 pin for those who only have the 4 pin.

I have thought about just wiring it up with the 7 pin and getting a 7/4 adapter. Problem here is if one of the neighbors "drops" it or it stops working/wiggles loose (have had this happen to me) they will be stranded or possibly at fault in an accident.

What says those who are smarter than I?

 

[stamp11127]

Another option is to back the same way big trucks do, turn your hazards on. The red light doesn't affect your vision at night.

 

[allanbegg]

Your thinking is right. I have both a 7-Way and a 4-Way mounted on the Expy to work with different trailers.
Your approach is to do the same thing, but on the Trailer instead, to work with different vehicles.

Allan

 

[USMCBuckWild]

Your thinking is right. I have both a 7-Way and a 4-Way mounted on the Expy to work with different trailers.
Your approach is to do the same thing, but on the Trailer instead, to work with different vehicles.

Allan

Thanks!

This has taken a backseat since life has gotten in the way. I'll do a "how to" write up and parts list.

 

[USMCBuckWild]

Update to this:

I went ahead and did some work on the trailer (reinforced the shody and weak trailer sides at the rear where the gate is held in up position), and re-wired the entire trailer. I went ahead and purchased a 7 pin plug and wire 8' long with a waterproof junction box from mictuning. I also grabbed a heavy gauge 4 pin plug that was 8.5' long. Snagged a set of cheap led brake/amber turn signal/reverse light trailer lights and some 18ga 9 conductor stranded cable (9 seperate 18ga stranded wires inside a single heavy wall insulation) and a 4 pin led blinker convertor. I have a variety of marine grade heat shrink connectors and tubing.

Part of the design I had in mind for the trailer was a plate to mount the box in between the cross rails (which are 2x2 mild angle iron). I ran a single piece of heavy walled 3/4 id pipe for a clean and protected wiring conduit. I drilled a 7/8" hole in each cross rail and welded the pipe in place to support them and provide a little more rigidity. I also ran lengths of the heavy wall pipe to each side of the trailer on the inside of the rear most crossmember where the ramp/gate hinges are. The trailer gets some off-road use and making the wiring more impervious to snagging or damage from debris was part of my plan.

I ran the 2 seperate plug wires through the draw bar (2x3 rectangular tube with plenty of room under ball coupler with no chance of pinching) and reinforced with the adhesive lined heat shrink tubing to the junction box. I mounted the blinker convertor behind the outlet of the junction box. I paired up sets in the 9 conductor wire coming out of the junction box (to ensure adequate power to the lights and redundancy in case of wire/connector failure) since the trailer lights are 5 wire models. The only 'single run' wire is to the reverse lights since they are the only non-legally-required lighting.

All the wiring is connected with the marine grade heat shrink/solder connectors and sealed with the marine grade adhesive lined heat shrink tubing.

All in all, I over-thought and over-built the entire system. But, do it right the first time. The wiring should outlast the entire trailer. Haha!

Overall use so far is phenomenal. I get ALOT of compliments on the lights, especially having actual amber blinkers. I can see soo much better when backing the trailer anywhere and the lights are "protected" by how I reinforced the rear corners. As for the 2 pigtails; they run out the tongue and loop to the passenger side where they are held in place by small spring clips and a brass ring bolted to the draw bar. No chance of them dangling or dislodging and coming in contact with the roadway.