[macgyver]

I went through my Suburban Furnaces during our first winter. Mud Daubers got into ours as well. There is a Micro Switch that tells the furnace that there is Air Flow and if restricted and/or not working will cause this problem.
I also replaced the Circuit Board with one from Dinosaur Electronics as recommended by other Gurus that corrected a similar issue. Here is a link to a recent post I made about parts;
http://newellgurus.com/showthread.php?tid=2615

PS just noticed that I need to post the part number for the Circuit Board so I will update that in a few minutes. I am also going to PM my cell # to you if you need/want to talk about this.

Thanks for the info I should give a new board a try , it's amazing how many components are on that board when there are only about 4 wires hooked up to it ?