Solelnoid...or wiring/fuse from the solenoid?
A solid 'Yes!' to those recommending checking the ground and using the multi-meter to confirm continuity. But...(isn't there always a 'but'?)...I would have saved 5 hours of stress last summer if
I'd started with the simple items first!
Similar condition as described: batteries fully charged w/ nothing at the control panel & switch. Zippo, not good. On a M-25XP, there's a fuse coming off the starter solenoid and wired to the block. If I'd checked this fuse 1st, problem solved in less than 5 minutes. Unfortunately, I didn't know this fuse existed and I began with the complicated and messy stuff first.
Upon inspection, after my 34th phone call and following that mechanic's advise to "...check the continuity from the solenoid; find the red/yellow wire and test it". I found the red/yellow wire and the wire
had parted between the solenoid and the fuse! Vibration over 25 years will have that effect.
10-minutes round trip to walk to an auto garage and pay $4.21 for a new fuse assembly and spares fuses, 5-minutes to install and 'vrooooom!', engine fired and we were off. Whew.
Here's a pic of the culprit, part of the 'Rogue's Gallery of Dumb Stuff That's Happened'...