Newmar Dutchstar fantastic fan problems

[Thawley147]

Replaced circuit board for rear bath fantastic fan in my 2015 Dutchstar. Still not working, but now the other two fans quit working. Replaced fuse in KiB box to no avail. Looking for any thoughts. My Newmar dealership service rep is stumped.

Thank you

[Gary RVRoamer]

Need some basic diagnostic info to isolate the problem to a likely cause. Is there power to the non-working fans? If no, you need to troubleshoot the 12v supply lines and grounds. If yes, troubleshoot the fan units themselves. If a 12v supply problem, do all the fans share the same 12v power lines, or are they separate? The fact that one quit before the other two suggests separate. Do the fan units have remote wall switches for on/off? Do they have the optional wall control panel that lets you change fan speed, rain sensor, etc. And what model of Fantastic are they?

[Skip Y]

Quick question - does the vent power open and the fan doesn't start, or won't the vent come open. If the vent opens but the fan won't start check the limit switch. If nothing works check the switch (since you've already confirmed the fuse is OK), or check for voltage at the fan connection with switch on.
Next contact Dometic thru the web site. There's no challenge in 'stumping the dealer'!