Have any idea where the black & white wires hooked to the solenoid terminals go to? Looks like someone used a household extension cord to do some half-assed wiring job for something. It might be in your best interest to see what's at the other end, it may explain and be a part of your problem.
You need to look at the harness plug where the starter button plugs into the main harness and see if the yellow/red tracer wire is one of the wires in the plug, and then locate that wire where it exits the harness to go to the solenoid.
