The model number provided isn't complete so I couldn't take a quick peek to see what you've got, but here's some basics.

Are you sure you've got 240v to the unit? Just because the unit runs doesn't mean you're getting 240. The motor runs off of 120V. Check your house breakers.

Do you have a meter to do some testing? If yes, are you getting 240v to the terminal block where the cord attaches? Where are/aren't you getting power?

By saying all parts on the back, what all did that consist of? Element, thermostats, etc.?

Motor switch comes into play. But considering I couldn't find the model # you've listed anywhere, I couldn't come up with a wiring diagram. If the diagram is on the unit still, you'll need to look at the motor section. You'll see there is a contact on the motor switch which has to close when the motor starts which completes the circuit to the element.

Afraid I'm striking out trying to find a wiring diagram. Did you also change the thermostat on the blower housing?

Well your down to the start switch on the motor or possibly a bad contact in the timer. Without a diagram I've pretty much exhausted all I can do. Maybe someone else will chime in who can come up with a diagram.

If memory serves me right, the resistor had to do with the timer advancing, not the heater circuit.