reviving this thread, maybe some use to others-

Looks like its the electrical part of the ignition switch, the jiggle method worked for a few days, now I only get the "hum"

Ordering a switch today and will be looking for tips

 

Installed a new electrical portion of the ignition switch and guess what -we are back to click and hum.

Checked/cleaned tranny ground strap.

Battery test is next, maybe the wiggle and start was not a "red herring".

Ideas and inputs appreciated as always