Originally Posted by
redford
Check for current draw. Turn lights on. Try to start engine. Do headlights dim?
If so, you're getting current to the starter. Either the battery doesn't have enough power to turn engine over, wiring (current path) is bad, starter is locked or engine is locked.
If lights do not dim, you're not getting current to (and through) the starter. Look a solenoid, wiring, park/neutral switch.
Guys, guys, not to be rude but I know how to diagnose electrical problems as I stated before. The basic methods you mentioned apply for all vehicles and I have lots of experience with numerous vehicles just not this one. Thats why I'm asking if there is any oddball switch on this particular truck/engine combo that I am not aware of that doesn't apply to the average car/truck that might be the cause of not starting.