If you have the supply wire to the glow plug loom use it. Otherwise make one from Cat Parts. Then run it to a solenoid that is powered from the battery. Then ground one of the light terminals of the trip circuit of the solenoid to the mounting bolt. Make sure the mounting bolt has a common ground with everything else. Then run a control wire from the heat terminal of the heat/start switch to the other light terminal of the trip circuit of the solenoid. Your Heat/Start switch must be Cat or close equivalent. It needs to have a heat terminal that is powered in Heat position and in the Start position. That way you can preheat and continue to heat while cranking.
Later Bob
Mcclaar,
Here you go.
[attachment=20330]Cat_Schematic_3306_engine_Serial#3N..jpg[/attachment]
Kelly
Kelly,
Thank you. This should help a bunch!!!!
Andy
Interesting that Cat has abandoned the use of a separate solenoid to power the glow plugs. Result is more of the wiring and switch/es having to handle much higher amperage. Might be part of your problems.