I have always had trouble with my machine starting with ignition. Starter will always click but most generally not engage. Now my ignition feels messed up and hard to turn with key and also will not at all actuate the starter. When I turn the key over, my neutral relay makes a soft horn/buzzing noise and 40 amp fuse gets hot.
it sounds like you need a new ignition switch, and then new contacts in the solenoid. Or you could use a multimeter to see what's happening if you don't like my guesses.
I'll take anyones recommendations at this point. I did order a new ignition switch so should be here Friday. The starter was new a year or so ago and did not fix the issue of sometimes not engaging to start. Have a permanatatly fixed screwdriver on board as a key!!!!!!!
It could be a relay clicking and not the starter, that's where the multimeter comes in. Use some alligator clips to make some test leads, hook one to ground and one to the small wire on the solenoid to see if it's getting juice when you try to crank it. then you know which direction to look next.
I would start with tracking down all grounds. Chassis ground, block ground, cab etc. Make sure all are clean and tight . As a rule, whenever I get an ignition switch that feels "gritty" or sloppy, I'll swap that rascal out. Especially in an open cab application. As mentioned earlier by Delmer, a voltmeter is gonna be the cheapest path to an accurate diagnosis. Throwing parts at it might ease a symptom to a greater(simpler) problem.