Troubleshooting MaxxAir Fan 4951KSC Fan Not Working
Updated 07/02/2026 | Published 06/29/2026
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Question:
Our 2019 Momentum 320G Maxx Air Fan Model 4951 KSC, will open, however when I turn the fan on it immediately shuts down. I have disconnected the rain sensor, and also the 12V power trying to reset the board. New board??? What part no is the correct one for this unit?
asked by: Kevin R
Expert Reply:
Hi Kevin,
It does sound like you may be having an issue with the control board. To make sure the issue is the control board, measure the voltage while the fan is in the ON position. If the voltage of the fan drops from 12V to 0 volts when the fan shuts off, that usually means it's the control board. If the voltage stays steady but the fan stops, that points toward the fan motor being bad. Also inspect the board for any corrosion, burned up components, or water damage in case some moisture got to it.
If you determine that the control board is the issue after testing, you can use the MaxxAir Replacement Printed Circuit Board for MaxxAir Powered Lift Roof Vents w/Reversible Fan part # MA10A21275K to replace your control board.
Where is this vent installed on your 2019 Grand Design Momentum?
Product Page this Question was Asked From
MaxxFan Plus Roof Vent w/ 12V Fan and Thermostat - Manual Lift - 10 Speed - White
- RV Vents and Fans
- Vent
- Roof Vent
- Manual Lift
- 12V Fan
- Reversible Fan
- Plastic
- White
- MAXXAIR
more information >
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