I bypassed my ignition switch and went to the solenoid connector. I ran a wire from my positive side of my battery to the push button switch, and from the other side of switch to the red/yellow wire of solenoid. I took the green wire from solenoid to frame ground.
But I will check for a loss ground on the side of engine.
I am troubleshooting the same problem, turn the ignition switch you get power to the dash, no crank, no brake lights. I ordered a brake pressure switch on the master cylinder, I will replace it next.
Did you locate the brake switch on the Massimo Buck 400? I am having the same problem. I can’t find a switch following the brake linkage. How ever there is a pressure switch on master cylinder. Could this be my problem?