The fantastic vent fan in the bedroom has a problem.

[TenOC]

I have a Montana 2014 3100RL 5th wheel. The fantastic vent fan in the bedroom has a problem. The motor that closes and opening the dome continues to run whether in automatic or manual or off mode. It runs in the direction to close the dome. Manually I can open and close the vent dome, but the motor continues to run even when in manual mode. Tomorrow, my son will get on the roof and see if there is something wrong with the dome switch. I’m too old to get on the roof. I tried calling fantastic vent service but they were closed for the day.



Any troubleshooting or other suggestions are welcome. Thank you.

[MrWizard]

If you have a speeding iron, you can use it for diy plastic welding and melt the tabs and secure the lift motor, you can use zip Ty's as plastic welding rod material

[wa8yxm]

Sounds like you found it.. I don't like glue when I can use bolts (But since my FF was 100% manual I don't know if you can bolt it down)

Alas I have done a lot of things like that however.

[TenOC]

I think I have found the problem. When the dome is 90 to 95% close the automatic versus manual crank pops out about 1/16 to 1/8 of an inch from the automatic position to the manual position. The dome stopped moving in the motor continues to run. If I push the crank fully up into the automatic position the dome closes and the motor stops

I do not know if the motor splines are stripped or not.I need to do some more experimenting to see what causes this problem. But as of now I have a solution to the problem

Update: I do not think (?) the splines are stripped. I think the lift motor has broken free from the white plastic housing that holds it. Only two small plastic tabs that were melted in place to hold the motor. I have ordered a new motor from Amazon. AND I have attempted to glue the lift motor back into the white plastic housings. This way I will have a backup.

[DancinCampers]

I believe the small motor that opens/closes the lid stops itself based on current draw. I would remove the crank handle and inspect the splines and gear box. It may also be the control board,

[joerg68]

There should be a mechanical end switch that engages when the dome is closed. I had a corrosion problem there once, but on a less sophisticated Fantastic Fan model.

[wa8yxm]

On a hunch something is on the rain sensor.. Like a bird dropping.. or something both conductive and sticky (Tree Sap?) Option 2 is a short on the sensor lead. Option 3 is a bad control board. Option 4 is a stuck relay on the sensor board.

Oh and if there is an OPEN/Close switch.. that's about the list I think.