Ralph Mowery wrote, on Mon, 22 Dec 2014 14:43:24 -0500:

Now that all that went on, it might be time to check the air flow
switch. It will be something after the blower mounted on the air
chamber. It is a switch that will probably show open and when you have
air flow it will close. If it does show open, and never closes when the
blower starts up, you have low air flow. Either the blower is not
turning or the switch could be bad. If it shows open, hook the two
wires together and see if the furnace stays running. Or place your
meter across the wires and see if they stay closed. You can probably go
to ground from one of the contacts and one side will always have voltage
and the other one will not. Get on the one without the voltage and see
if it ever gets the voltage.

Do you think this might be the air-flow switch, bolted into the side
of the air chamber?
https://c4.staticflickr.com/8/7527/1...d908b870_b.jpg

I tested it and it seems to be a short (which is probably what it
is supposed to be).
https://c4.staticflickr.com/8/7540/1...18ee847c_b.jpg

It might be a temperature switch though... or a fusible link?
https://c4.staticflickr.com/8/7498/1...4fb55b63_b.jpg