I have an Atwood 8500-IV furnace, it keeps blowing the 12vdc fuse. Blower comes on, Igniter clicks 3 times and the fuse blows. Blower is free spinning, no wasp nests, bird nests, junk, spiders, or any other obstructions. I can see ignitor, but cant get to it, need to see if its clean on gas side where it ignites. Afraid of removing heater and ending up with gas leaks lol. Any help would be appreciated, Thank you