Heater Problem

Thanks for the responses. I found that a dirt dauber had built a nest on the fan blower causing it not to turn therefore blowing fuses. Hope this helps others
John

Time delay relay could be defective. Try disconnecting fan motor an try it again.
There is a circuit breaker on the fan housing that should trip it were a bad motor. Yes this circuit breaker could be bad. Pinched wire in the motor circuit?

Dick, I am not running the generator and the 15 amp fuse is recommended.
Old-Biscuit, every time I change the fuse and turn the t-stat on, I hear the furnace click then it blows the fuse. This has happened several times.
Thanks to both for the input.

Generator....110V AC output
Furnace......12V DC input

Furnace motor bad, control module shorted........you need to check the 12V DC circuit. Suspect the motor/motor circuit.

12V DC power (fused) is 'on' all the time to timed delay relay (either a stand alone one or one that is part of module).
When t-stat closes power from t-stat goes to timed delay relay or module which allows the power to go to blower motor.
IF that is when the fuse blows......motor or motor circuit causing blown fuse.

Fuses blow because the current exceeds the fuse rating. Could it be that the generator is not putting out as high a voltage as it should thereby requiring more current to operate the heater?
I've told you more than I know...