HELP!!! 12VDC Trailer Lights on 24VDC Deuce

Guys I need help, input, guidance, hand holding or what ever will work.

I have figured out the pin out on the trailer light hook up on my Deuce. I have created a nifty new trailer light connector from the connector piece that I found in the truck when I got it and a four pin flat trailer wire connector. I have a new class IV drop hitch that I have installed and a spankin new 20ft 14K Lbs trailer to put behind it all.

By now you have guessed my problem. 12VDC trailer lights & a 24VDC Electrical system on the Deuce. I want to have the best of both worlds. I want to be able to pull the trailer behind the deuce when I need to as well as behind my pickup or other 12VDC vehicle when I need to.

I started out thinking that I could get some LED light that would work both 12VDC and 24VDC. I have searched around but cant seem to find that combination in a 4 inch square Stop/Turn/Run along with two small amber side markers.

So I said OK I’ll try to step down the voltage. Ohms Law and some resistors ought to do the trick. So with that in mind I worked out the following.

The trailer lights produce 0.7 Ohms of resistance. They need 12VDC. Quick math says 12V divided by .7 Ohms equals 17Amps of current draw.

This doesn’t seem right because the left and right turn fuses for the trailer lights are 10Amp fuses. Seems like they would pop if the draw was 17Amps. So this is perplexing.

Next thing I did was take a 12VDC Battery and hook to the trailer light to make them glow. Then I put my multi meter in series with the positive leg of the circuit between the batt and the light. I didn’t get ANY kind of amperage reading. Again this seems weird.

I went to one of those Ohms law calculators on the web and it look like if I series in two .35 resistors into each leg that I will get the amperage down to a reasonable amount as well as produce 12 VDC. So I kept pushing down that road.

I called a local electrical supply house looking for resistors and the guy said “Man you are making this harder than it needs to be. We have these nifty little voltage regulators that will do the trick but you have to tell me what the amperage draw is so I can sell you the right one.” Aggghhhjhh!!!!! This is nuts….

Anyone got any good ideas how to make my 12VDC trailer light system work on my deuce and still work on the old pick-up?

I’m going crazy here.

Thanks,

I do the same thing, only towing 24vdc trailers with 12vdc trucks- Change the bulbs out with 24vdc bulbs! The bulbs are exactly the same, just 24vdc! It does take a little time, 10 min or so, but it works like a charm, no fancy electronics, no additional wiring or lights. Just change them back when pulling with your 12vdc truck.

Easy and simple. I have a padded ammo can on the trailer toung that I keep the bulbs in. I usually go ahead and leave the 12vdc bulbs in- I pull it more with my pickup then with the deuce. I have a little magnet I painted '24' on one side, and '12' on the other. I just flip them on the ammo box when I change the bulbs so I remember which type is in the lights when I hook up the trailer.

I'm a huge fan of K.I.S.S. (not the band...)

Buy some 24v bulbs... swap them out as needed?

buy a set of these, and hope for the best? http://www.pmlights.com/products.cfm?cId=1&fId=62&pId=2343

Contact one of the big 3... Grote, Truck-Lite, or Peterson, and see what they offer? Someone is going to have the lights you need.

This is what I did, may not be for everyone.

http://www.steelsoldiers.com/index....0&start=0&postdays=0&postorder=asc&highlight=

about the ohms, you are measuring the cold resistance of the lamps. When they are lit, the resistance is much higher. The hotter it is, the higher the resistance.

What is the part number of your 12-volt trailer light bulbs?

When I asked about the part number of the trailer light bulbs I had JRBAMATEX's trailer bulbs in mind. My fault, I didn't state who I was addressing. So...

JRBAMATEX: What is the part number of your 12v trailer light bulbs? Or are they marked with the power rating (in watts?)

Westfolk: $35.00. Wow! That's more-or-less what all the resistors would cost if resistors were used instead. And ya, sounds much easier to deal with than building something out of resistors. Maybe more efficient also, depends what's in the guts of the thing.

- Allen

Another thought.... why not use military LED composites, and LED markers...

Believing the KISS principle I just run military composite taillight assembly on 12V when tow with civ vehicle (spliced in a flat 4 connector into the mil light harness). Bright on enough 12V to make me happy. Put 24V bulbs on your trailer and leave them.

I think I saved this from CGarbee's site, a useful bulb conversion chart...

If you want to use the dual-filament type 1662 24-Volt lamp instead of the usual 1157 12-Volt item, be aware the contacts are reversed. What was tail will now be stop/turn & vice versa.

Not insurmountable, but can make you crazy if you didn't know.

dg

Sorry for going dark on you guys. Took my son out to the deer lease to mess around for a couple days. Fishing shooting and motor cycles. I think he had a pretty good time.

Anyway, thank for all your help and input there are some really great ideas on here. I like the voltage regulator approach. Thought that it was pretty cool but started getting to complicated for me when capacitors had to be added.

Now I am thinking of going back to the LED lights that work on 12 & 24VDC. One thing though. Is it that ALL 12VDC LEDs will work at 24VDC or only some of them?

Also I like the converters. I am going to obtain a few of these. They will be good for other things to. Like radios and running trailer breaks.

jodka was looking for the PN's to my trailer bulbs. I took them out and these were the numbers on them

tail/turn/stop = 1157 TAIWAN
side marker = 168

thanks all,
JR

An adapter.
Notes: The trucks M35A2's socket is used for 4 conductors(R turn,L turn,Ground,tail). The 24V relays in box send 12V to the trailer(R turn,L trun,tail)as needed.There is a 4th relay under the dash (for the brake lights/e-brake controller).An additional supply wire(a 3/12 ext cord) goes to an aux plug/socket on back of M35.It carries a 12V feed, e-brakes supply(12V) and brake lights(12V).

The box rides loose in the equipment trailer's utility box. Doing it this way allows 24V trailers to be hooked to deuce, as designed, while keeping the 12V trailer (7 pin)unaltered for use with my 12V dumptruck, or when/if loaned out to pals).

If I didn't need a 12V trailer I'd have swapped the 15 or so trailer lights(trucklights) with the rather expensive 24v items(avail at NAPA). E brakes suck.An air brake trailer is on my list.
JimK

Great news... I think. I went and picked up a random 12vdc marker light LED at the Auto Zone today. I hooked it to the trailer light connector on the deuce and it worked just fine. I figured I would risk a $7 marker light before blowing out a $50 set of tail lights. Now that the marker experiment worked well I will proceed with the change out of the incandesant bulbs to the LED's.

Thanks for all your help and I will get back to you with the results of the completed project.

JR

Success!!! I have added LED trailer lights including side markers and it all works great. I added a vehicle end 7 pin connector to the end of my deuce trailer connector and everything works like it came from the factory that way. I made this waaay to complicated to start with. The simple solutions are always best. Here are some pic’s.

Oh yeah and thanks to everyone as always for all your help and input.

JR

Sorry, had to resize em. Pic's didn't work the first time

JR, how about some pics of the packaging the lights came in? Or the details of Brand, Model, Store, and such? Most the 'Walmart' type LEDs dont list dual voltage... so it would be nice to know where to get a known working set. Also report back after you have some 'time' on them too.

Good point. A little data might be helpful.

I got the lights at Northern Tool because I knew that I had seen Peterson Piranha lights on the rack there. The reason I wanted the Petersons was because when I got the little side marker light as the sacrificial tester at Auto Zone it was a Peterson Piranha light. So I figured I'd stick with the brand that worked.

The PN for the Tails is V840L (left light/Roadside) and assume V840R for the other side (can't find that box now). At any rate it seems that ALL the Peterson Piranha LED lights will work because the side markers that I installed were not the same as the one I tested with. However they all worked great. After I hooked everything up to the truck and checked to make sure all the signals and everything worked properly I left the Right Blinker running while I went inside to to get the camera. (maybe five minutes of run time) No problems and no funny smells. I'll let you know if they go out anytime soon.

Pic's of the packaging below.

Thanks!

Nice touch on the screen in the background!

JR, I'd like to see the hitch you put on your Deuce.

Have any pics of the hitch and the install?

Thanks

Clinto