I was thinking maybe for now a crude electronic solution might work, something using a power transistor and oscillator to convert from 24V to 12V inline through PWM (pulse width modulation). It would be a very crude approximation of 12V (rapidly pulsed 24V) averaging out to 12V, but since we have no electronics in the circuit and heating is really our only concern this may work fine. Perhaps even wire it so it flip flops between 2 12V output lines one to each glow plug on a MEP-002a or to each pair of two on a MEP-003a. It has been too many years since I dealt with this kind of stuff, but perhaps some of our more electronic inclined people could chime in, this would at at least help as long as there is a supply of the 12V glow plugs out there, and should be a simple plug in cheap module.
Ike
p.s. there might even already be 24V to 12V PWM modules built for other purposes that we could convert to this use (solar charge controllers, etc.)
I posted this same idea else where. I think the simplest solution, if 24V glow plugs become extinct and we have to start using 12V glow plugs, is this. First - install a heavy gauge wire (gauge will depend on current draw) to the + terminal of the "bottom" battery. This is the battery whose - terminal is connected to ground at the starter. Second - install a HEAVY DUTY spring loaded "NO" (normally open) switch on the meter panel and connect the wire coming from the battery to it. This wire will have 12V on it. Third - run another HEAVY gauge wire from this switch to each of the 12V glow plugs. Fourth - tape over or install heat shrink tubing over the ends of the original 24V glow plug wires to eliminate the possibility of them shorting out to ground. The original 24V glow plug wires and the GLOW PLUG position on the original start-prime-run switch are no longer needed or used.
To start the generator:
1. Put the start-prime-run switch in the PRIME position as before and let the fuel pumps run until the system primes.
2. Push the new spring loaded glow plug switch "IN" to activate the new 12V glow plugs. After the glow plugs "light" (30-60 seconds) release the new spring loaded glow plug switch
3. Turn the original start-prime-run switch to START and the generator should start and run as usual.
If 24V glow plugs ever go extinct and if all that are available are 12V glow plugs, this will eliminate the need for 24V to 12V voltage converters. Some have suggested that a resistor can be used. However if you do the math, I think the size and wattage resistor needed will make most people shy away.
cuad4u PE Electrical Engineering