Troubleshooting A MaxxAir RV Vent That Keeps Trying To Close When Its Already Closed

Question:

Max air deluxe fan randomly beeps and tries to close the lid, even though the lid is already closed

asked by: Tyler S

Expert Reply:

Most likely the circuit board for your MaxxFan Deluxe Roof Vent w/ 12V Fan # MA00-07500K is faulty and needs to be replaced, but there are a few things we can check first before replacing it with part # MA10A21275K.

A lot of the time there could be a power drop that shuts the vent off and then when it comes back on it "wakes up" and tries to close but doesn't know that it's already closed. In some of the trailers I've worked on when I cut the power and turn it back on the vents will start the fan for a few seconds and then shut back off.

First, remove the inner trim piece to get to the wiring. You'll want to check the wiring for any damage or loose connections, this is especially important for the ground since a bad ground can cause electronics to malfunction in weird ways. Next take a multimeter # PT89ZR and test the voltage at the vent to see if it's getting a full 12 volts.

If not, you have a power issue and will need to trace it back to the source to see where it's dropping. If it's too far of a run from the power source to the vent you could just need to increase the wire gauge to prevent the voltage drop.

If the power and ground is fine then you'll need to replace the circuit board.