MaxxFan Model 4751KS Will Not Shut Off

Updated 03/20/2020 | Published 07/23/2019

Question:

My vent will open and shut but can’t shut off the fan nor control the speed. It runs on high all the time. I had to pull the fuse to stop it. I disconnected the wires to the fan and the vent will still open and shut from the control panel. I bought a new control panel from you folks and it made no difference.

asked by: Carol A

Expert Reply:

I took a look at your order and saw you had purchased the Replacement Key Wall Control part # MA00A03550K but the issue you are having with your MaxxFan Model 4751KS is the circuit board, the Replacement Circuit Board part # MA10A04751KS so this what you need to replace.

expert reply by: Conner L

Tank

3/18/2020

We have a wall mount control for our maxair. On the second speed it dims the bathroom light to the point it gets dark in bathroom. The other speeds are fine. The lights are L E D the rv is 2018 Montana.

Chris R.

3/19/2020

That's a new one to me....It certainly sounds like the bathroom light and the fan are sharing the same circuit, and for some reason when the second speed is selected, it's pulling power away from the light, or at least causing the voltage there to drop for some reason. There has to be some kind of wiring issue up there that's causing a type of short. I would inspect both it and the light's wiring to make sure everything is in good condition. You might even have an electrician come and take a look to ensure everything is sound.

Tank

3/19/2020

I couldnt find any loose connection or frayed wires. The fan motor pulls 3.4 amps on startup on all speeds only 2nd speed turns lights off they flicker on other 3 speeds then com on

Chris R.

3/19/2020

This is a pretty strange/unique situation. I honestly think the next step is to try and have a local electrician take a look at everything. I'm really not sure what could be causing just that second speed setting to dim that lights like that. It could be coming from the fan, the bathroom light, or the wiring/power in between.

Tank

3/19/2020

U dont think it could be the switch

Chris R.

3/20/2020

That's a possibility, for sure. Have you checked the wiring behind the switch? There could be a short coming from there - make sure it's securely grounded and that there aren't any loose connections or frayed wiring.