We have an old INTERTHERM Central Electric Furnace Model: FEH-012HA. The blower operates fine but we are not getting any heat. I figure that the heating element or a relay turning it on is bad, but the schematic/wiring diagram is old and faded.

Questions: Where can I find the wiring diagrams, parts lists etc and are the parts still available for this old model?

I would try contacting a Nordyne dealer in your area. If no luck there, try Nordyne directly.