does anyone have a wiring diagram for my 85 f250 6.9L...the previous owner for some reason rewired the glow plugs to a push button on the dash. i would like to wire it back to the way it was and if there was a problem change it. i dont like the fact that if someone else drives my truck and doesnt know about the pushbutton or if they hold the button to long and maybe burn out the plugs. If anyone could help that would be great!

 

Just leave it. The pushbutton is a better setup. You will spend so much time trying to figure out what's wrong with the glow plug system. If one of the glow plugs goes bad it will effect the system, is the controller is bad, if the coolant temp sensor, if even one of the controller to glow plug wires has to much resistance, all these will easily and drastically effect the system.