Thanks for the reply.
Yes. The limit switch and fusible link is located right above the burners and both were checked. The circuit is closed, which the schematic on the back of the furnace cover indicates is normal.
I believe this is not a counterflow furnace, as I believe the blower is located below the burners and the schematic didn't indicate more than one limit switches. (but I could be wrong)
You can view some photos of the furnace at:
Carrier Furnace - a set on Flickr (sorry for the crappy camera phone shots)
The schematic does indicate a relay is located on the circuit board, but I have not,and won't have time til NYE, checked that out.