Chinook RV

The three speeds on my FF drive me crazy. Even the lowest speed uses over 1 Amp and is noisy. So I've often wanted to add a variable speed control.

Yesterday I ordered a 5A capable PWM controller from Amazon. It even has a built-in switch detent at zero that turns off all but about 10mA usage. Undoing four screws (two long, two short) let the facade drop. I disconnected the short wires going from the Fwd-Off-Rev switch to the motor, so it could all hang down by the speed selector wires. I then clipped off the incoming power wires and removed the original speed switch. (Or you could leave it in place and drill a new hole for the new one and put them in series. Personally I didn't want to have to explain all that to other users!)

In order to get the new controller to fit where the old one was, I had to Dremel a groove for the board and other space for parts. Then I was able to just get the front nut on the shaft reaching through the hole. (I had almost cut the white negative wire from the direction switch too short.) To cover the full original hole, I decided to use the much larger original knob. After putting it all back up, you'd think it was still stock. But now the knob smoothly rotates almost all the way around, with a huge range of speeds and power usages, from 0.2A to the full 3+A. Ah, bliss!

Took just $10 and less than an hour, mostly carving out rear bumps with the Dremel to make the new short shaft stick through the original hole.

Sweet mod. I'm surprised that the plastic didn't shatter when you were working on it. Mine was so brittle it didn't take much for it to fall apart.

You know your stuff.

You can see one crack in the fan plastic baseplate in front of the PWM board in the last photo. Another one was starting at 90 degrees from there.

When I saw that, I stopped tightening the nut too much!

Sooner or later I'll want to go back and apply some glue to the back of those.

Cool mod! I had bought a PWM switch but hadn't done anything with it yet. Was figuring I'd have to put it elsewhere somehow. But maybe not!

This is how the newer 13-speed (if I have that number right) Fantastic Vents work, but you can only get them with an IR remote. Which makes it annoying to control it right from the fan (say, in the bathroom). Plus, they're spendy.

I'll note that there are plenty of PWM controllers available, especially on eBay from China, for as low as $4.

Some have a separate speed controller knob, etc.

I chose this one simply because it met the necessary specs (DC 12v, at least 5A), it was small, and it was available immediately from Amazon. I'm a sucker for anything that's Same Day Delivery

Agreed. There were almost too many to choose from! I first bought one with exposed guts, and then a second one where they are boxed. I have a marine fan that doesn't go as low as my favorite Hella Turbo and thought I might try one on that. Think I may put the PWM up in the overhead cabinet (where fan is mounted) with the knob projecting through to the room side. All theoretical at this point though, whereas yours is real

Another great write up. Thanks.
I had one temporarily installed in my ceiling fan and the capacitor exploded after a couple weeks. I think it was rated 3A, from ebay. Nice while it lasted.

I got this one running 24/7 at about 1/4 speed. Let's see how it does.