Furnace fan won't turn on

My furnace has decided to go on strike. When I turn on the thermostat nothing happens, no fan, nothing. It was working fine two weeks ago but now it's dead. Two years ago I replaced the t-stat with a 2-wire when I removed my air conditioner. It's always worked well until now. Wires are solidly connected to the thermostat. Any suggestions?

Thanks. Electrical is not my forte, but I will forge ahead. Probably a few days before I can get to it, but I will let you know what I find. 

Next time it doesn't want to run, bump, slap, kick it.  If that makes it run, you likely have a bad spot in the commutator, or open winding in the armature of the motor.  

The furnace didn't originally go into lockout mode did it? To get out of lockout you have to turn the stat all the way off (or otherwise remove power), then back on, just turning up the temp setting won't do it.

Offgrid, your comment about lockout got me thinking, so I found the manual and went through the trouble shooting guide. I ran out of propane the 2nd day of our trip and I'm wondering if the low gas tank had moisture in it (I was using up last year's propane) which, according to the guide, might make it go into lockout. I had a spare bottle of fresh propane, but if the old gas was still in the line at the furnace maybe it stayed in lockout until the moisture was somehow purged? Not sure what the mechanism for that would be, but it makes sense to me. (Not that making sense to me is significant.)