MaxxAir Fan problems and solutions

[Fadeagray]

Thanks — that’s very helpful. I’ve been wondering about whether a rebuild could be functional. Maybe you could say a bit more about the cleaning and re-assembly procedure you find works best? I had real trouble getting my old fan back together. I still need to try it on a 12v source to see if it works at all.

Also, are those bearings sealed on both sides or open on one side as shown in the Amazon picture. I have a ton of old high end, serviceable bearings that would work well, but are unshielded on one side. Been wondering if they’d work with the open side in the cups and not exposed to the debris in-side.

Great info!

The bearings are identical to the Maxfan bearings. The part number stamped on the bearing is the same as well.

I’ll post up additional detail on cleaning and assembly in the next few days.

 

[Fadeagray]

Thanks — that’s very helpful. I’ve been wondering about whether a rebuild could be functional. Maybe you could say a bit more about the cleaning and re-assembly procedure you find works best? I had real trouble getting my old fan back together. I still need to try it on a 12v source to see if it works at all.

Also, are those bearings sealed on both sides or open on one side as shown in the Amazon picture. I have a ton of old high end, serviceable bearings that would work well, but are unshielded on one side. Been wondering if they’d work with the open side in the cups and not exposed to the debris in-side.

Great info!

These are my steps for a rebuild.

Pictures:
- Tools Used
- Cleaning Supplies
- Remove Snap Ring
- Remove motor body screws while holding motor together.
- Remove end cap from shaft end.
- Push down on shaft while removing motor body.
- Pull each brush away from motor armature. Wrap brush wire over fingers on brush plate. Remove motor armature.
- Detail of brush plate showing brushes and fingers on brush plate To hold brushes off motor armature. Remove brush plate from end cap.
- Blow off motor parts then clean with QD Electronic Cleaner. Blow off parts to dry. (no picture). Replace bearings if necessary.
- Assemble end cap and brush plate. Ensure that wire pass through bushing is aligned with slot on end cap and that brush wires are held back by wires to fingers on brush plate.
- Install armature in brush plate and release wires from fingers.


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[Fadeagray]

Continued

- Hold down on armature shaft while lowering motor body over armature / brush assembly. Make sure that wire pass through is aligned with slot on motor body. Magnetic force will make it hard to control. Make sure to push down on armature shaft to keep brush alignment with armatur. Now is the time to ensure that wire pass through is properly aligned.
- Install top cap.
- Install motor body screws. The magnet in the motor body will make it difficult to align screws with end cap. Hold the motor together while looking down at the top of end cap to align screws with screw holes. Tighten screws snug. then back of slightly. I like to make the final adjustment to body screw with the fan plugged into powers supply while running to ensure that I have preload correct and no squeaks.

Install motor and reassemble fan.

 

[dstefan]

Great write up and photos. Thanks! I think my biggest problem was reassembling the brush cap first and trying to insert into the casing. Will try the “reverse” way you’re doing.

I’d love to have a working spare on hand, so worth fiddling with some more . . .

 

[ramblinChet]

Here is recent and relevant information on repairing my MaxxAir 7500 fan after its circuit board failed due to charging LiFePO4 batteries at 14.40 Vdc. Credit for this simple and effective fix goes to an individual whose name I cannot recall.

For $10, I purchased two DC motor controllers, which were shipped to my door. After approximately one hour of installation, the fan was fully operational again.


I mounted the three-position switch (IN-OFF-OUT) and rotary knob (OFF, 0–100%) on the driver’s-side-forward corner of the fan in my Four Wheel Camper. This location allows easy adjustment from the bed and provides sufficient space for component placement and ventilation.


An external view shows the three-position switch and rotary knob. The configuration—switch, knob, and motor—is straightforward and effective. At full speed, the fan draws 36 watts; my typical setting consumes approximately 10 watts.

 

[dstefan]

@ramblinChet — That looks like a great bypass solution. Just to clarify — the rocker switch is for the automated lid opening? Or is it just power on off with an unused setting? And this replaces/bypasses the entire MaxxFan circuit board?

 

[ramblinChet]

@dstefan - thank you. The rocker switch controls the direction of the fan or turns the entire system off - the lid must be opened or closed manually. In short, you can remove the original board and have power +/- coming into the unit and fan motor +/- going out completely bypassing the board. Here is a picture from their ad:

 

[dstefan]

@dstefan - thank you. The rocker switch controls the direction of the fan or turns the entire system off - the lid must be opened or closed manually. In short, you can remove the original board and have power +/- coming into the unit and fan motor +/- going out completely bypassing the board. Here is a picture from their ad:

View attachment 886444

Seems like the cool thing about this is that you could use a completely different fan motor if they keep not updating the motor to a brushless design . . . assuming one could find the right motor. Is that a correct read?

 

[ramblinChet]

Seems like the cool thing about this is that you could use a completely different fan motor if they keep not updating the motor to a brushless design . . . assuming one could find the right motor. Is that a correct read?

You are correct and I am sure with a bit of research it would be possible to locate a brushless DC motor that would drop right in. This motor seems to do well though and I am able to enjoy an infinite range of adjustment from 0-34 W with it remaining quiet. If you find a brushless motor that fits make sure to share with us.