12v headlights on 24v system - wiring

[Prince]

I have two new 12V YELLOW sealed beam headlights (low and high beam) that I want to install on my 24V M38A1. I think they are 50W/60W (low/high beam)

Wire in series? Install resistor? Install 24V to 12V converter/s?

The series way has a problem due to the lights having two filaments (low and high), as I see it. I know that a pig-tail is needed from the middle terminals of the battery so as to protect the second headlight if the first one fails.

resistors or converters - how many and what will be schematic look like?

I would like the installation to be reversible by using pig-tails if possible. Simple solution would be to buy 24V lights, but I could not find them (as of now) and want


Thoughts?
to have the yellow lights ASAP. I found two new ones, albeit 12V.

 

[KaiserM109]

No good way. Resistors will dissipate as much energy in the form of heat as the headlights use. That will double the amount of current the headlight circuit pulls and would take huge resistors. It would probably blow fuses and/or breakers, maybe even overload wires.

 

[clinto]

As Kaiser said, not really feasible.

However, there are 24V military yellow lights available. DO a search for the yellow lights and you'll be richly rewarded.

 

[Prince]

Actually I have done a comprehensive search for 24V yellow headlights. I agree that they must be out there some place, however I have not been able to find any. One guy had "Amber" lights and I ordered them - they turned out to be "Red", and I returned them.

It is somewhat simple to connect the two headlights in series with just the low beam or just the high beam including a "balance" wire to protect the first light when the second light burns out - and to not lose the second light when the first light burns out (Christmas tree light effect). However connecting both low and high beam is a problem since there has to be a ground wire going from the first light to the high and low connection of the second light - thereby causing the second light to have both filaments lit (as I see it). But then again, I am a Mechanical Engineer (former Safety Engineer for the Space Shuttle Main Engines) and not an Electrical Engineer. Of course I don't want to turn this issue into Rocket Science!

 

[steelandcanvas]

I just saw a pair on that popular online auction site go for $82, is that a decent price for those "cool" yellow headlights?

 

[MarcusOReallyus]

Yes, it can be done!

But it will be a kludge, and will probably be a maintenance nightmare. Resistors, relays, and a lot of wiring.


As for putting them in series - are these three-contact lights? High, low, and ground?

If so, I don't think that's doable.


A 24 t 12v converter isn't cheap, but I think it's the only reasonable way to do this.

 

[clinto]

I meant do a search here on SS-

Check these out:

http://www.steelsoldiers.com/deuce/94670-inexpensive-yellow-head-lights.html

http://www.steelsoldiers.com/deuce/12035-amber-headlights.html

http://www.steelsoldiers.com/conversations/63130-source-mv-lamps.html

http://www.steelsoldiers.com/deuce/55436-headlight-questions.html

http://www.steelsoldiers.com/electrical/9951-source-amber-tinted-headlights-they-even-legal.html

http://www.steelsoldiers.com/deuce/18888-yellow-headlights.html

http://www.steelsoldiers.com/deuce/8171-yellow-headlights.html

 

[Prince]

Depending on where the Converter is installed in the wiring system, it could take either 1, 2, or 4 Converters - I think. If a single converter will work, then that is a possibility. More than that and it becomes to complicated.

I will continue my search for the 24V yellow headlights, using some of the contacts you guys provided, however I already have purchased a very nice new 12V set (Wagner) for $100. You pay for your toys!

I very rarely drive the Jeep at night (maybe never), so I could just install them and leave them not connected. Of course that would be the easy way and not the cowboy way!!!

 

[Prince]

I have continued to look for the yellow lights without success.

http://www.replacementlightbulbs.com/lamp4860.html
The above is the white light that is available "only as long as supplies last - they are out of production" $75 each!

Bulbdirect - no luck
Replacementlightbulbs - no luck

I will start looking for a converter today!

 

[papakb]

If you look around online you can find the transparent paint like they use on Christmas lights. Just paint that onto a pair of standard headlamps and be done with it. Unless you're replicating vehicles used in France, why would you want yellow headlights to begin with?

 

[Prince]

No real value to have yellow lights, however I like the way that they look. Same reason for having an Army Jeep in the first place. Why would anyone want one? Because I want one!

 

[jamboly]

I would sell the 12V lights and keep looking for 24V. They aren't very common, but do show up from time to time. I bought two at this years MVPA convention, but they were the last two the guy had. Try posting on wanted in SS clasified.

 

[Prince]

I will continue to look for the 24v lamps. HOWEVER...

I found a converter for $30 that is good for 480 amps. If I don't use it for this application, I can use it to power other 12v things from the Jeep.

SOLUTION:
I say this because I have another very simple way to power my 12v yellow headlights on the 24v system:


1. Install the yellow headlights, including jumper wires on each of the 3 prongs of each headlight. In other words, use a standard 3 prong plug on the headlight with military style connections on the ends of each
of the 6 wires. Then the headlights simply connect to the existing wiring.

2. Make a new jumper wire going from the positive terminal of one of the two 12v batteries (I have the battery terminals that you can add a washer type of wire connector to).

3. Run this new battery jumper wire under the instrument panel and connect it to a new on/off switch. Locate the switch at a convenient place or a hidden place. The switch needs to handle about 200 amps.

4. Run a wire from the new on/off switch to the "BAT" (actually is one of the two tall contacts on the dimmer switch - label may be "L" or "H") contact of the dimmer switch. A number of types of plug-in
connectors can be used depending on if you want it water tight or not. Use military if wanted.
You will have 1 male connector going into the dimmer switch (that was cut), 1 female connector coming from the new 12v wire, and 1 female connector on the existing 24v wire (that was cut). This way,
you can disconnect the new 12v power supply and re-connect the original 24v power supply when using 24v headlights.

5. If you like, you can then exchange the "indicator 24v lamp" in the instrument cluster for a "12v lamp". Otherwise the indicator light will be dim, since it will be receiving only 12v power.


Might sound involved, however there is only one 12v jumper wire, a light switch, and some connectors needed. Almost no cost. Just a little time.

When turning on the headlights for night driving, you will need to turn on both the new "headlight switch" (to get headlights) and also the normal light switch on the 3 lever switch (to get tail lights and instrument panel lights). No big deal.

NOTE: The existing military dimmer switch has 3 wires connected to it. ONE is for Power to the switch (coming from the existing headlight 3 lever switch OR our new jumper wire coming from the battery). ONE goes to the headlights and is for Low beam (leaving the dimmer switch). ONE goes to the headlights and is for High beam AND the high beam indicator in the instrument cluster. This wire branches off via a split connector a few inches from the dimmer switch, into the two wires (one for High beam and one for indicator light). If I have this right.

OK, I am on the solving the next problem - unless I missed something on this one!

 

[KaiserM109]

2. Make a new jumper wire going from the positive terminal of one of the two 12v batteries (I have the battery terminals that you can add a washer type of wire connector to).

BAD BAD BAD !! !! !!
Don’t ever split the drain on your batteries PARTICULARLY WITH SOMETHING HIGH DRAIN AS A SET OF HEADLIGHTS!
Recharging the batteries can only happen in a series which means the other battery has to pass all the charging current needed by the discharged battery. This will cause the battery you didn’t use to overcharge.
You’re trying to put lipstick on a pig. You have one of the most iconic Jeeps in the world; appreciate it for what it is and don’t try this silly stuff. Take my word for it; I have a degree in Electrical Engineering.

 

[papakb]

That's as good a reason as any when it comes to MVs!!

 

[Prince]

I have since read about the out of balance charging of the batteries and tend to agree with you , unless I balance a 12V load on each of the two batteries which I don't plan on doing, there is a potential for problems - maybe major. I appreciate your response. And yes, I really do think a lot of my M38A1 which I am now making many corrections to for the sake of originality ($$$). I actually drove the M38a1 and M151 while in the Texas Army National Guard in the 1970s. I also went to light vehicle driving school at Ft. Polk and drove the M151. I was in the second group to train with the M16 (as I was then told in 1969), so I have some changes to my Jeep that may seem not correct by date, but in fact are - like having my early M16 (AR15 lower) mounted in my M38a1. Anyway, we all do what we want with our vehicles unless someone else is willing to use their money and then I might really consider doing it their way. LOL!

Therefore, I did already order a 24v to 12v converter good for 480w that I plan on inserting in the power wire between the headlight switch and the dimmer switch. One wire cut with connectors.
Should I ever find the yellow 24v headlights, I will simply remove the converter and re-connect the power wire to the dimmer switch. I will check the output of the converter with an ohmmeter and with another headlight just to be on the safe side before I connect the expensive and rare yellow headlights.

It may sound funny to go through all of this trouble, however I know men who do mush crazier things than this with there hobbies.

I very very very rarely drive the Jeep at night, and then for short distances - so I almost don't need headlights in the first place (of course I would like to have them connected).

you can see some photos of my Jeep at: cardomain.com In the upper right hand corner of the page, in the search box, type in: gormanwpjr
You will find my Jeep among my other vehicles. I have since made more improvements to it, but it looks about the same.

 

[m35a2cowner]

Wasn't there some way to get a different voltage (12 V) off of the 24 V system? I think I remember something about the M151 (GMCs) having some sort of dual voltage switch. Would it be possible to make some sort of system (isolated electrically) from the truck where you could draw only 12 V from each battery for an add on light system? I am NOT an electrical engineer but it just strikes me that I have seen it or read about it. I could be wrong.

 

[VPed]

I think the easiest way is with the light circuits in series (common terminals jumped together). Apply 24 + to one lamp and negative to the other side. You have to switch both the plus and minus between the hi and lo filaments so that is done with a double pole/double throw (DPDT) relay.

 

[AN/ARC186]

Or you could try these and equip them with a 24 V hi/lo lamp.
http://www.usfreeads.com/685090-cls.html
http://www.quadratec.com/products/97016_01.htm
http://www.kchilites.com/wp-content/themes/kctemplate/pdf/KC_2011Catalog.pdf

 

[MarcusOReallyus]

The converter will to the trick for you, but I fully agree with KaiserM109. Don't do it that way!

Watch your grounds when using a converter. Things can get hairy if you only think you know what you're doing. And when it comes to grounding and converters, well, a lot of people find out they only thought they knew what they were doing.

At least you don't have to worry about it being positive ground!

But don't worry - if you get it wrong you'll know soon enough.

Don't let the smoke out!