I bought an old used gas furnace for my garage. When I looked at the wireing it was all undone. So now I have to wire all the electric and the thermostat. I called the maker Armstrong furnaces but they did not have any diagrams. Can anyone help?

Exact model number?

Note you might look on the back side of the blower motor access door. Almost all furnaces come from the factory with one

Will there be a airconditioning unit used with this furnace. Let me know and I will try to help you.

Look online and see if you can find a diagram. If it is the electric and the control wiring that is farily simple. Let me know and I will assist you in any I can.