Hey,
I'm Matt. I have 2003 Ford F150 supercrew xlt. I have a set of 24v LED lights and am wanting to hook them up to my truck. I am currently deployed to Iraq and looking to get the stuff I need to hook them up for when i get home. So if any one could help me. PLZ

 

Welcome to the forum.....IF you have 24 V LED lights you wish to install, you are going to have to figure out what "dropping resistor" to use.
LED,s are extremely low voltage,and in most all Automotive situations,there is a resistor in series with the LED to supply the correct operating voltage.
NO resistor and theyre toast(in a heartbeat)....I would do some research to find the proper resistor,once thats done they should be dirt cheap.

 

If they are not bright enough on 12v . You will have to add a small extra battery to your truck with a charging switch and wire it in series to get 24 volts for your lights.
I'd just get new leds

 

n5926g,,the leds are 24v he only has 12v thus he doesn't have to drop the volts.
I think the resistors you are refering to are to make the low watt leds
work with electronics that use a higher watt light bulb.

Though I'm not an electronics tech.

 

The resistor interface is going to be a higher resistance than that of a 12 volt system.If he hooks up 24 volt LEDS on a 12 volt system,they wont be the intended intensity.(approximately half)You were correct in the comment about putting a small battery in series with the original 24 v leds.this would in fact give them the correct input voltage to maintain proper light output.The downside to this is that the "additional" battery likely wont be of the rechargable type,and after it has "run down" the 24 volt LED,s will again be at roughly half intensity.
His best bet is to either purchase 12-14 volt LED,s and bypass all this theory,or calculate the required resistance to make the 24V led,s "think" theyre being fed what they want.