A 24 to 12 volt step-down transformer should not be too hard to find. A 240 to 120 step-down will work as well, but it will be very heavy and large. You just need half the windings on the secondary side as on the primary side. You can also use A step-up transformer (if this is all you can find) and wire is backward to step down. Since it's D/C to D/C it's fairly straight-forward.
What may be easier/better is to get an inverter for 110 volt power. These can typically take 24 volt input with no issues and give 12 volt output (optional on some models, so check first) as well as 110 volt A/C power for running your margarita blender.
To check polarity of the vehicle, see which cable from the battery is attached to the frame. Negative ground attached the (-) battery terminal to the frame, while positive ground attached the (+) battery terminal to the frame.
I may be wrong, but I'm fairly sure ALL 24 volt trucks are negative ground.
Also, an expert on the big military generators may be able to provide a pin-out to get 12 volts out of that generator by halving the windings. I imagine it is not easy, or impossible, or more people would do this...
Owner: James Leach Global Expedition Services.
1995 110 Regular