After installing my RV fan in the floor of the van (which is my favorite mod of all time now!), I noticed it’s a pain in the butt to operate when sitting on the drivers seat. It’s rare that I am in the drivers seat for a long time but sometimes it’s the best view in the house. So I decided to put in a blower motor directly under the driver seat. This is not a new idea… and several PI’s have mentioned this idea to me recently. But the most credit will go to Paul LeGrand. James Fleet sent me his write-up which saved me a lot of time!

Before I start, I want to say that this blower works great. It pulls the cool air from under your car and blows directly onto your legs and cools the car down fast. And unlike the floor vent fan that I wrote up, you can install this blower in a car or SUV as well…

Total Cost: Around $100

I used a Johnson Pumps of America 54124 Marine Flange Mount blower. However, you can use ANY 12V Flange mount marine blower.

I then went to Lowes and bought some drain covers. You will need to do this with your blower to make sure the threading works properly. This is not a necessary step, but I wanted to prevent anything large from getting into the motor and breaking it.

Below is a picture of the cap for the intake side

Below is a picture of the cap for the exhaust (inside your car)



Next you will need to find a place in your floor to drill. As I wanted to have the air come directly onto me when I am in the drivers seat, I drilled through the floor right in front of the drivers seat. You will NEED to lift your carpet up to make sure there are no wires that you may accidentally drill. In my Dodge Grand Caravan I actually had to relocate some factory wires. You will also need to check under the vehicle if there is room to mount the blower flat against the floor.



Next you will need a hole saw based on the size of your blower. Drill through the floor of the vehicle. I recommend drilling through the bottom as you will allow more room for error that way.

You will need a dremel or razor to cut the hole in the carpet.

You will need to cut 2 pieces of wood. I used 3/4 inch wood I bought at Lowes. I forgot what kind… but it was the strongest I found.

You will mount the first piece as pictured below using 4 long screws with flat heads. Pre-drill the holes so as to not crack the wood. Please use stainless steel hardware so it won’t rust. And please throw some Rustoleum spray paint on any metal you drill through to avoid rust as well.

I also used a LOT of clear, super strong, weatherproof silicone between the carpet and the floor and between the carpet and the wood. This will help you avoid air leaks and noise.

After you mount it, you will want to use the same or slightly larger hole saw and drill the hole in the wood.



Next you need to mount the blower. Pre-mount the blower, and mark where you will be drilling. Then drill the holes and use 3-4″ bolts with washers on both sides and nuts to mount the blower to the wood block. Do not over-tighten as you may crack the wood.

Next you will need a marine deck plate that is slightly larger than your blower. My blower size was around 3″ and my deck plate was 4″. You will want to use a hole saw and drill a hole for the deck plate in the second block you have cut. See below to understand.

You will also want to use silicone between the two wood blocks.

Lastly, I took this opportunity to install the drain plate on the exhaust part of the blower.

I also had to use my dremel to cut out a little room for the bolts and washers to make sure my 2 wood blocks are flush.



Next I used some black matte finish spray paint to paint the wood for cosmetic purposes. I put on 3 coats. I also mounted the deck plate. using 3″ flat head screws. I recommend pre-drilling the holes so as to not crack the wood.



I didn’t like the look of a white deck plate so I replaced it with a black one…



Next is time for the electrical part of the installation.

I used 14 gauge wires. I routed them to my fuse block with a 20 amp fuse. I will be writing an article on my electrical mods soon which will explain how to setup your batteries and fuse box. If you don’t have a fuse box, use an inline fuse and mount the wires to your battery.

Initially I used a toggle switch to operate the blower. However after a few days of field use, I decided to use a motor speed controller. The blower is quite but not silent. At full blast it can be slightly heard at 20-25 feet away. At halfway power it can barely be heard at 10 feet.

I used a RioRand RRCCM9NSPC DC motor controller 10V-50V 30A. I mounted it directly behind the passenger seat so I can easily reach it from the drivers seat.