2 sets of running lights?

[madjack]

....if you run two harness's take one and reverse the plugs so that you have a male/female on the trailer with the 12v vehicle with one matching end and the 6v car with the opposite end, this will keep from hooking up the wrong set at the wrong time(hope this makes some sense)
madjack

[Arne]

I'd use 12v lights powered by 6 volts...... unless they were so dim as to be dangerous... Somehow, unless it has a v8 in it, I don't think you'll be going very fast......

One thing that makes lights much more visible is to paint the inside of the light fixture white..... it makes it the light more visible and mellow. I do it on all of my trailer lights...

[asianflava]

I was thinking, like Kevin said, isolate the wiring from the frame. Then hook the positive and ground thru a DPDT switch. One side will be reversed from the other. Flip the switch one way it will have negative ground, flip it the other and it will be negative ground. You just have to make sure that you have it flipped the right way before connection the harness.

[GregJ]

I'd try the 12v bulb first, it will probably work.

The LED lights are probably polarized so would only work in one direction unless you put a bridge rectifier behind each one.

If you want to get a little fancy, a diode lets current flow one way and not the other. So, two 6v bulbs in series with a diode in parallel with one. If pointing the right way will also do the trick. A resister of the right value in place of the second bulb would also work, but would be kind of large…

Either will cost an extra $5 – $10 and no switches to worry about.

The two could be combined for a 6v LED. Let me know if you need more detail...

[Larwyn]

I was thinking, like Kevin said, isolate the wiring from the frame. Then hook the positive and ground thru a DPDT switch. One side will be reversed from the other. Flip the switch one way it will have negative ground, flip it the other and it will be negative ground. You just have to make sure that you have it flipped the right way before connection the harness.

How about isolation relays on the 6volt tow vehicle. The relays would be activated by the 6 volt system but utilize the trailer battery to power the 12 volt lights. A simple 6 pin connector could be wired in such a way that when pluged into the 12 volt vehicle the trailer battey would be charged (or ignored) rather than used as power for the lights, but with the 6 volter connected to the same plug the trailer battery would supply power for the trailer lights. No relays needed on the 12 volt vehicle. Of course the isolated ground would still be needed.

[Brad Lustig]

I'd thought about using relays and will look into it when it comes time. It would definitely make a unique setup and probably fairly simple

[Larwyn]

I'd thought about using relays and will look into it when it comes time. It would definitely make a unique setup and probably fairly simple

Yep, I think I made it sound more complicated than it really is. The 6 or 7 way plug on the trailer would be wired as it normally would be for any trailer (with a charge wire for the trailer battery). Just isolate the ground from the chasis. As long as the trailer battery is charged you would have 12 volt lights. Would only require 3 relays on board the 6volt car. Then there would be nothing to remember or do (other than keeping the trailer battery charged), just plug into either vehicle and go. The vehicle lights operate the relay, the relay operates the trailer lights. Same as they are doing on some of the newer 12 volt vehicles with low current lighting ckts. only the main 12 volt source is different.

[Brad Lustig]

I've got a 12v jump-pack in the trunk of my Dodge for the stereo so I'd probably run it off that.