Dale,
The controller must sense an increase in current (i.e., the vent lid has reached its limit of travel) before it will shut off the lift motor. If the lift mechanism splines are stripped the motor will continue to run.
All three of our Fantastic Vents stripped the coupler between the lift motor and the lift arm for the very reason that Joel mentioned.
Fantastic offers upgrade kits that provide a significant improvement over the OEM, I upgraded two of our vents with the “non-remote” kits. However, when it was time to upgrade the third vent, I discovered that only the remote-controlled version was available (at least when I was looking). I’m not sure that I want the remote-controlled version.
The coupler is pressed onto the lift motor shaft so if the splines on the lift arm are still intact, for about $5.00 and an hours’ worth of time you can make a new coupler and have a functioning vent. I did this with our third fan when I found out that the manual upgrade kit was not available. This won’t work if the splines on the lift arm are also stripped.
Purchase a splined long shaft (1 3/4”) RV window crank handle, found in most RV parts stores for about $5.00.
1 Using a hammer and drift, remove the damage coupler from the motor shaft.
2 Cut the splined end of the window crank handle to the same length as the original coupler.
3 Drill out the non-splined end of your ‘new’ coupler using a drill bit that slightly smaller than the diameter of the motor shaft
(use the original coupler as a gage for the drill bit).
4 Using a vice, press the new coupler onto the motor shaft.
I ended up installing vent covers on all three vents. In addition to being able to use the vents when it’s raining, they significantly help with the sticking vent lid issue.