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This is a 12 VDC unit and so the generator has no real function here other than charge the batteries via the converter system. I doubt that you needed two motors as one of these usually goes quite a few years, even with lots of use. Dinosaur Electronic makes a good timed delay relay for these. If you have an outside inspection panel, this is pretty easy to trouble shoot with a 12 VDC test light. About $5 at most hardware stores. I am adding a link to the Atwood Service Mnual for this model. Print out a copy as there is a lot of good information in there. IF the motor comes on when you ask for heat, it isn't the relay. You can hook up the motor directly to a 12 VDC power source and see if it comes on or not. Get back to me if you need assistance with the testing. All follow ups are included in our fee. http://bryantrv.com/docs2/docs/hflamefurn04.pdf
The converter may be shorting out and most converters work on two 30 amp fuses. You can test it with a meter. A good converter should put out about 13.7 VDC. Be sure that the house polarity is correct. It won't make a difference in the house plug, but it will in the RV. That, too, can be checked with a meter. I thought this had a time delay relay issue?
Get a test light or meter and this isn't hard to do. Does the motor come on or not when you ask for heat?
What is the 10 amp fuse you are blowing? The heater is supposed to have a 15 amp fuse. the reverse polarity fuses in the converter are either 30 or 40 amp.
Did you print out the manual I gave you?
I don't see this going anywhere so I will opt out of the question. I have fixed over 100 of these over the years and see this question almost every week here. You don't seem to want to do what is required to solve this and you probably have to take it into a shop. Sorry it didn't work out. I will put your question up for another tech to offer something if they want.