Amos, let me summarize where I think we are on this.
You think the motor is at fault. From what I see in the Suburban manuals, unless your model is one with an external access door, you will have to remove the furnace from the RV to access the motor as others have said. You should probably post the furnace model number to get better advice.
Unless you have a "park model" RV, they don't normally use 120v AC. You are blowing a 12v fuse so you need to disconnect all of the wires to the furnace to make sure it's that which his blowing the fuse. Just disconnecting some 120v wires isn't sufficient.
Does anyone else have any better ideas?