My furnace / A/C doesn't work & the HVAC dude can't make it over until Sunday.

I hope I can at least give it a temporary fix, because it's frickin' hot.

The A/C compressor works, but the main furnace / A/C fan does not. I can hear / feel the PC board click on like it wants to turn on the fan, but it doesn't.

Any ideas? Thanks much!