6 volts tail lights for trailer

[Dutch_Jeeper]

So, electrical is not my strong point, i did some reading on the 6 volt system but not very elaborate yet

I need to convert the lights on my trailer to 6 volt, the current light units are from a Wrangler and there are no 6 volts lightbulbs for it. Besides that it does'nt look right behind the CJ3a I'm still looking for the same CJ3a taillights but also found some new Ford Model A lights which look like a good fit and that can use either 6 volt or 12 volt tube lights.

I have a few questions about the wiring. The Jeep already has a 8 pin socket, wiring is taken straight from the taillights. I still have to look into how it's set up exactly and which pin is what.

But about the wiring for the trailer though.

-For 6 volts the thicker the wire used the better right? For the 12 volt lights i did not use the thickest wire possible (1,5mm2). So not to loose to much current and brightness of the 6 volt taillights, replacing them with thicker core wires (2,5 or 3mm2) is better!?

-Ground!? The taillights are now setup grounded through the socket, there is/was a separate pin for ground on the TJ. Is this the same for the 6 volt system or do the 6 volt lights need to be grounded to the trailer?

I've had a short talk to someone who converted his Bantam trailer from 24 to 6 volt for his 1943 Willys and he told me he had a hell of a time and a lot of problems!? I did not go into it at that time, well did not have the time as he was proudly going on about how every bolt and nut and accesory from shovel to helmet was from 1943 also. It is one beautifull Willys used for "keep them Rolling" events and parades during the 5th of may (Official liberation of the Netherlands)

However it can not be very difficult imho? Just use the right wires and replace 12 volt units with 6 volt and make sure the socket is setup correctly?

Right?

Thanks for any tips

[OkieFarmJeep]

This is an old post, but for those reading them here are a few answers. This is a classic ohms law question and a Google search will explain that. The simple answers are yes, you need much heavier gauge wire.  The voltage drop going back to the trailer is pretty stiff, but this is doable if done right and you pay attention to detail.  (Google that as well, voltage drop, there are online calculators to help) Where most people get in trouble in these situations is ground.  Your Jeep grounds back to the battery via the frame.  For this reason it is important to have good ground paths. In the 3A this was done via a bare braided strap.  You should have the engine, frame and body all tied together with ground straps and good clean metal contact.  Next one of your pins will need to carry that ground back from vehicle ground to the trailer. You can't count on the hitch to always do that properly.

[Dutch_Jeeper]

Thanks Okiefarmjeep,

I did not have the time untill this weekend to wire the trailer up, the Jeep has been to the shop for the gearbox. They also checked the wiring on the trailer socket and said it was OK.

So i wired up the trailer according to the official guideline for a 7 wire socket, hooked it up and turned on the lights� well offcourse it did'nt work lol. If I turned the turnsignal left on, both lights in the left socket started signaling together and the right one signaled up and down (first the top light then the bottom) If i switched to the right turn signal all lights started signaling together� :-? had to be a ground problem, since the lights were also very weak.

So i unhooked it and checked the socket on the Jeep, it was kindoff a mess:

The blue wire was supposed to be the ground wire:



This is how the taillights were connected:

The right Green/Blue/Red/White is the cable going to the socket. The other going to the right is to the front of the Jeep.



Looked to be dirty and corroded so i turned to the socket. It should have been hooked up correctly but looked like a mess:

Here's the correct schematic:

Yellow: Left turn signal
Brown or Blue: Constant +
White: Ground
Green: Right turn signal
Brown: Right taillight
Red: Brake lights
Black: Left taillight



This is how it looked, could not tell what was what:



After:



And connected to the Jeep after cleaning all the old wires, did not have to cut of much to get to clean wire. The corrosion did not get far into the wires. I cleaned the battery wire and ground on the Jeep and made a new clean ground for the trailer lights.



Now offcourse things do not go that easy lol� No change when i hooked it up and tried again lol

Thinking the new ground was still not good enough i ran a wire straight from the battery to the new ground i made to see if things changed. They did not, unhooked everything again stripped the wires again and cleaned everything again, hooked it up and still the same.

Quit for a while on the wiring and did some odd jobs i still had to do on the Jeep. The I had a brainfarth to run the wire from the battery straight to the trailer. Then it all worked as it should and the trailer lights were nice and bright� Because i restored the trailer recently and a friend of mine borrowed it for his holiday without a problem it never crossed my mind the ground problem was in the trailer. I made a good ground on it when restoring it but apparently what's good enough for 12 volt is not good enough for 6 volt� almost a day gone by drinking beers, pondering the problem, searching and rerunning wires lol untill I thought about the trailer ground and fixed it in 5 minutes�

So lesson learned, always start with ground�

[OkieFarmJeep]

Glad you got it! Chasing bad connections can be frustrating. Bad grounds stump many.  If I may add to your good job: I would clean the back sides of the harness plugs with electric contact cleaner and then cover it all ( Back side / inside) with dielectric grease to prevent future corrosion. On the splice strip- your last pic, I would clean and cover the wire entry points with liquid electric tape.  Then pack the screw heads with silicone grease used on the plugs. This will give you years of trouble free service. An ounce of prevention prevention is worth a pound of cure.