Fantastic Fan PWM modification

I rarely use my Fantastic Fan because speed 1 sounds like a jet on takeoff roll at about 85% thrust. I wanted to use the fan without having to put in earplugs and still have it move some air through the camper.

I looked through a couple of other threads for this topic but was never able to see an easy to understand wiring procedure. I found one on YouTube that was easy enough to understand so even I could do it. I just did the mod today and so far it works very well and I cannot hear a hum or buzz from the PWM. The fan can easily be put back to stock wiring in just a few minutes if desired.


Both the 3 position speed switch and the fan direction switch still function like they do pre-modification. The PWM also has its own off switch.

However, this is only a 2 amp PWM with a self resetting fuse, and the fan can draw 3 amps on higher settings. I only tested it on max speed for a few seconds, probably not long enough to heat up the resetting fuse. If it doesn’t work for my purposes I can easily replace the PWM with one that can take higher currrent. Since I only use the fan on low settings this 2 amp PWM might work out

I was originally going to put in a new MaxxAir but decided to try this out and so far it’s works well. Really nice to have 100% fan speed control.

Here’s what I ordered online

RioRand Low Voltage DC 1.8v 3v 5v 6v 12v 15V Motor Speed Controller 2A PWM 2PCS
Amazon.com

However it is only a 2 amp PWM so you may need one that operates at higher current if you like to run the fan at high speed. There are similar 5 amp models available.


ANCIRS 30pcs Semi-Insulated Piggyback Spade Connectors, Quick Disconnect Piggyback Spade Assortment Kit, Female/Male Cable Crimp Terminals, 22-10 AWG
Amazon.com

Some 16 awg wire. Black is (+) White is (-) in my 4 wheel camper.

And some liquid electrical tape to protect the PWM board from moisture

STAR BRITE Liquid Electrical Tape, Black - 4 OZ Can with Applicator Brush - Waterproof, UV-Resistant, Dielectric Sealant for Wires & Cables, Marine & Home Use (084104
Amazon.com

The RioRand speed controller is limited to a 2A current draw. Doesn't the fantastic fan draw more than that? I'm too lazy to check right now, but I think it's higher. I worry that an overloaded PWM speed controller will have a high failure rate.

Personally I never sleep with the fan on. We just leave the fantastic fan lid up and a few windows open. We've never had a condensation issue.

The fan draws around 3 amps. The PWM has a 2 amp self resetting fuse. Seems to still work ok on the low to medium speeds I used for a couple hours. I didn’t leave it on high speed for long enough to heat up the PWM resettable fuse polymer to its amorphous state.

In any case if it doesn’t work out for me I can easily replace this 2 amp PWM with a 5 amp model, but so far its working for my purposes.

I just did a similar mod to our fan, we were of the same opinion, even at speed 1 it was way too fast, so we used it infrequently. We have used it more on our last couple trips than we did for the previous seven years of trips combined. Looking at the amp draw on the Victron app when just the fan is running at our preferred speed it is about a quarter of an amp (down from over an amp on speed one prior to the mod). I'm glad I did it.

Similar experience as you. Used the fan more in the last few days than I have in the last 5 years. Draws from .25 to .50 amp on my preferred speeds, never need it set higher than that. Very nice to finally have a useful fan. Should have done the mod years ago.