Troubleshooting MaxFan RV Fan that Only Sporadically Works

Updated 10/21/2025 | Published 10/12/2025

Question:

From day one our Unity leisure Van equipped with two max air vents both have proven to be quirky only opening electrically on rare occasion. . Vents have no reverse function and came with no remotes. It’s as though the rain sensor is too sensitive. With fan speed NOT on zero , ON/OFF switch ON The OPEN/CLOSE SWITCH seem to only energize motor in close position although every once in a long while it delightfully does open. Most often soon there after closes as though it was wet from condensation as it certainly wasn’t raining!

asked by: Tom R

Expert Reply:

Hey Tom, I would check to make sure the power circuits to both fans are solid but otherwise it does sound like the circuit boards are out on both. If you can get me the model number of the fan I can let you know which circuit board you would need.

Most likely you need the part # MA10A21275K since you said it's supposed to be reversible, has a remote, and a rain sensor. This fits the following:

MaxxFan Plus: 00-04500K, 00-04700K, 00-04800K, and 00-04900K
MaxxFan Deluxe: 00-07000K, 00-07500K, 00-08500K, 00-08700K, and 00-08900K

expert reply by: Jameson C

Tom R.

10/15/2025

I didn’t say they were reversible or have remotes. Logically the rain sensors were inhibiting opening most often. So I simply opened vents and carefully cleaned off the rain sensors . Thereafter the open/close switches worked ??