Does any one run a 24 volt system. or know if the gm alternator swap will support 24 volt lighting?

in order to convert to 24 VDC, you would have to make a lot of mods - many of them time-consuming.

What is the purpose/goal of this conversion?

I have some kc 4000k HID lights that are for a 24 volts system. I wanted to see if it would be easy to use if not im going to sell them.

post the model #s there might be a better solution out there

Wild

model # is 665a

Ahh, now I see, these are Military spec lights.

The best thing to do, besides change the ballast to a 12V one, would be to
add a second battery (dual batteries), but wire the lights with a 12V relay and
feed the 24V to the ballast to drive the lights, it's a simple wire the pos to the
neg of the other battery, and use other pos and neg to power the lights, but
use a 12V relay for ease of wiring and just put the 24V thru the contacts to
the lights.

Got it?

Wild

yep.  one question. with the extra battery will it hurt any of the electrical stuff. I dont thank it would but just wana be safe. yeah they are left overs from iraq we never used.

Ahh, now I see, these are Military spec lights.

The best thing to do, besides change the ballast to a 12V one, would be to
add a second battery (dual batteries), but wire the lights with a 12V relay and
feed the 24V to the ballast to drive the lights, it's a simple wire the pos to the
neg of the other battery, and use other pos and neg to power the lights, but
use a 12V relay for ease of wiring and just put the 24V thru the contacts to
the lights.

Got it?

Wild

At some point that second battery is going to need charging - so you're going to need another relay (DPDT) that lets you break the serial configuration and reconnect in parallel, when the lights are not in use, so that it charges from the alternator - unless - you need to use the lamps when the battery is flat - in which case you'll need a second alternator just to charge the second battery - oh - wait a sec, that'll give you common grounds ...

Just swap the ballasts man, it'll be easier - way less wiring and relays (and sparks.)

wont i need to swap the bulbs out too.

No bulbs should be the same, but 5K would be a whiter light I thought

Bulbs & ballasts I believe are 'matched' - 35W bulb needs a 35W ballast, and so on - so as long you get a ballast to match the bulb you have and the supply voltage you need, you should be fine.

Practically speaking (Me? Practical??), I would sell them.

Life is too short to put yourself through the agony of throwing large amounts of time and money at a project whose result would only create bling and maybe some extra light.

I'm just sayin'.....

yeah im with you on this one ack, ive decided to get rid of them. one because i dont have a place to mount them and two i rather put the money into something that will help out on the trails. I dont ride at night. So im going find someone who will want them. Great information from everyone though.

You might want to check with military vehicle sites.  Since most of them still have 24v systems on board.