I just worked on my work partner's this past weekend that would not stay on. Hers is an '18.8 3790RD with the Atwood furnace. It had a code of 3 flashes and then 3 seconds off and repeat. The furnace had the updated seal so no water inside, but her board is in the middle of the unit, not on the bottom. It would ignite and then go out after 3-5 seconds. Our dealer was still open late Saturday and I called and spoke with the service manager. Given the code, he said it was an internal fault and would have to be taken out and tested, but just as we started to hang up, he suggested that I wiggle both the red power wires going to the board as he stated that at times condensation builds up under the spade bit covers and causes a lack of contact. So, I wiggled them around, tripped the reset and the unit worked well the rest of the weekend. So, I now have plans to take mine out when it gets back from the factory and put dielectric grease on my terminals.
2016 Montana 3790RD Legacy Edition
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