Sorry, title should say Central. Too fast with the fingers!

I'd say it's a broken foot switch. It shouldnb't be too hard to remove and inspect the VacPan for 'something broken'. It'll probably be easiest to replace the VacPan.

The wire may have come off the clips that hold it to the vac pan. The "switch" is very simple. If you can get the vac pan unscrewed, check the wires on the side, and short them with a screwdriver or coin (it's low voltage) - if it still doesn't work, detach the wires and short them together.

If it still doesn't work, then a splice has gone bad, most likely. Each valve should have the wire from the next valve down the line daisy chained to it, and the splice made at the connection in the valve.

Figure out where your machine is, and follow where the piping runs from there. The vac pan will probably be spliced at the nearest valve, check the wiring on those. Black to black, white to white. If not, then there's another splice or the wire's been cut somehow.

If the vac pipe is visible in the basement, you should be able to follow it and the wires to any other splices.

If all else fails, they do make a wireless remote switch you could change over to (see the link for one example,)
but I'm sure the fix will be simple. Start at the vac pan.

Here is a link that might be useful: Remote vac switch

Alan, thank you for that detailed response! It started working briefly over the weekend, but then stopped again last night (I sweep alot!). It does sound like a loose wire. Hopefully we can resolve it!

Thanks again!

You're welcome. They're quite simple, just make sure the pan connects up right with the vac pipe when you put it back.