Military Vehicle Repair: 1986 5/4 ton glow plug system, mitchell manuals, brush fires

Question
We (Lempster NH vol. fire)have a 1986 surplus truck for brush fires.  We are having problems with the glow plugs coming on to start.  The light will flicker at higher engine revs. (no plug engaugement.) I have replaced the GM #12034592 controller module and ignition switch.
 I noticed the plugs will work in the accessary posiition, but not in the ignition position. I can't find a schematic of the wiring for the system.  All data and Mitchell manuals have a very differt system listed. Electrical end of a car is no problem to me.   Jim  

Answer
Hello Jim, Well the glow plug system on these are pretty simple, but it does sound like more of an electrical problem. What I can do for you is if you will send me your address, I will send you an ETM (electronic technical manual)This CD will have all Repair manuals the Military produced for these vehicles. It also will have a pretty good wiring scematic in it and trouble shooting section.It does requir adobe reader to read it,but I think it is on the CD also.