Fast blink or very slow blink?
The Atwood on my Rig occasionally I had to mess with the wires going to the blower. indications were a short but. not exactly a short. never did figure it out. but I finally got it to work reliabialy.
When it Failed. Fan would not run
For other reasons I replace the original T-Stat (The FRONT A/C was the T-Stat) with a simple mechinical (20 bucks from Ace or Aco forget which) and a toggle switch to insure OFF. I added an LED and resistor. the LED would blink dim/bright/dim/bright when it failed. This is why i'm thinking short.
And as I said I never did figure it out. Just got it workign.