DIY

Sprinter Passenger Van Roof Top AC Removal and Conversion to Maxxfan Powered Vents

Why Remove the Factory AC Unit?

The Factory roof top AC unit on the Sprinter is engine powered by its own compressor and designed to keep the interior cool when loaded with passengers. Unfortunately the unit will not function with the engine off and it’s worthless while camping. It also eats up a lot of valuable roof top space that for us could be better used for roof racks, solar panels and powered vent fans. Last year we put almost 12k miles on our van and tested it in temperatures up past 100 deg F., in all but the hottest temps we found the dash AC proved to be sufficient and it should be even better once the van is fully insulated.

For now I’ll be installing a couple MaxxFan Deluxe unit’s on the roof. The Maxxfan units will be great when camping to create a breeze inside over the bed and ensure efficient moisture removal while sleeping at night. I’ll also be adding a roof rack with solar panels and the space gained from the AC removal will allow us to hang out in our chairs up on the roof rack while at camp.

Supplies that I used:

AC Removal

First up remove the interior in preparation for AC removal and insulation. Start at the front and work your way to the back of the van. I didn’t take pictures of the removal process but do have before and after shots. There are some good videos on Youtube of the headliner removal process.

Before…

And after headliner removal.

Removing the side panels. The trim around the windows can stay in place since insulation can be pushed up into the open areas with the trim in place.

Pile of interior parts

Next up is to remove the upper AC unit from the roof. First up take your van to a shop that can reclaim/drain the refrigerant in the upper AC unit, once the unit is drained of refrigerant your ready to start the removal process.

Using my buddy Mike’s Shop at Vanlab….nice heated shop to work in. Thanks Mike!

In the next couple shots I’ve already completed a lot of the smaller prep work. At this point you should remove the interior refrigerant lines from the AC unit, the lines run from the unit then down the A pillars. You will need to remove the plastic A pillar trim from both the drivers and passengers side so you can remove the AC lines from the interior of the van. There are two condensate drain lines that get removed at this time as well. Disconnect all the electrical connectors at the AC unit at this time.

Here you can see where I disconnected one of the two AC lines that go through the roof. Next remove the 10mm bolts that attach the upper unit to the roof, there are two 10mm bolts at each AC line connection.

Next move to the roof and remove the bolts from the plastic covers. NOTE: The roof is easily dented by knees crawling around on the roof. Use a piece of wood and put your knees on the board to prevent dents.

Remove the rear plastic cover. Note: The front cover is trapped in place until you remove the rear condenser unit.

In this shot you can see how the condenser unit is attached to the van with 6 studs. The nuts and washers you need to remove are buried under a bunch of white sealant (Looks like Sikaflex).

Next you need to uncover the nuts and washers. A screwdriver, putty knife and pair of pliers are handy tools here.

Once you have all 6 nuts and washers removed you need to separate the condenser mount from the roof of the van, which is also stuck down with more white sealant. For this task I used plastic scrapers, a hammer and some scrap pieces of wood. Start at the rear and use the hammer to drive the scraper between the mount and the roof, this will split the sealant and won’t damage the roof. As you move forward tension the mount by lifting up on the rear of the mount and installing a wooden block to keep tension as you go forward. Take your time.

Once the condenser unit is free hand it down to someone on the ground, the unit is really light.

Remove the front plastic cover and the foam block under the cover (pictured here). Mike at VanLab front and center.

The front portion of the unit is sealed to the van using a black adhesive sealant. To remove this portion use a wooden block and pry bar to slightly lift the edges of the unit while you use a long thin razor knife to reach in and separate the sealant. Go slow and work your way around the unit, place wood blocks under the lip as you go so the unit doesn’t stick back down to the van as you move forward. A second person is handy here for sure, it took maybe 5 minutes to remove the front unit using this method. Again the unit is light so hand it down to the person on the ground once it’s free.

Front unit removed.

Next up remove the wiring coming through the roof. The wiring has a round rubber grommet but is buried in white sealant. Have a person inside the van push up on the rubber grommet with a screwdriver etc and then use your razor knife to cut the sealant around the rubber grommet. Once free stuff the wiring/grommet down into the van.

With the upper unit removed its time to do some clean up.

Use a razor knife to trim off as much of the white sealant as you can without getting into the paint.

Next up use a automotive rubber eraser wheel to finish removing the white sealant without damaging the paint. This wheel makes quick work of removing the sealant.

Like all erasers it’s messy so wear a dusk mask.

From this…..

To this…in a couple of minutes.

Next up the condenser mounting areas. I will leave the studs in place and reseal the base of the studs once finished.

Don’t use the eraser wheel on the black sealant as it will gum it up and ruin the wheel. Wax/Grease remover removes the black sealant almost instantly, just put some on a shop rag and wipe the sealant off.

Sealed for the night.

Next up patching the hole and installing the Maxxfans…..

Patching the Hole

I fabricated an adapter plate out of carbon steel to cover the hole that was left behind from removing the Roof AC and to create a 14″ square opening for the front Maxair vent fan. I also fabricated 3 smaller covers that will seal up the smaller holes left by the AC wiring and hose connections. I covered the plates in primer then Raptor Liner. Raptor Liner is a bed liner material that is very durable and holds up great over time.

Note: If you search Ebay there is a guy in Oregon that makes pre-made adapter plates. There is also a CL Laurence sunroof that is a direct fit for the opening as well. (Sorry don’t have part numbers off hand).

Here’s the adapter plate in primer, getting ready for the Raptor Liner to be applied.

Raptor Liner fully cured. Here the adapter is setting in place and getting ready to be permanently attached.

The adapter will be bonded to the roof with 3M Panel Bonding Adhesive. Once bonded with this the panel will be rock solid!

Panel in place with adhesive applied. Here the panel is being held down with weights and clamps while the adhesive cures, no screws or rivets needed which helps to eliminate leak points.

Next up its time to cut the hole for the rear Maxxair Fan. A little measuring, marking and a skinny wheel made quick work of this task.

PRO TIP: Here we are cutting a blades width off each side of the rear fans base. By slightly trimming the base it will fit perfectly between the roof ribs without having to use a separate adapter plate to raise the fan base up, this gives a perfect fit and reduces the number of sealing surfaces and leak potentials.

The fan bases are sealed in place with Sikaflex 252 sealant…..no leaks here!

With the fan bases cured in place I sealed the screws on the bases with Silaprene and sealed the edges of the black adapter/seal off plates with black Sikaflex 221 (Not really a necessary step but can’t hurt. 🙂

Good coverage of sealant squished down inside, nice waterproof seal. NOTE: I would add a piece select pine to the bottom side for the screws to sink into and create an even better hold. I will later end up going back and adding these wood strips.

Getting the Maxxfan Deluxe fan unit ready to install.

And installed. I’m happy with the way they turned out, nice and clean. Having the two fans when camping will really be awesome!

Rack installed and Dicor Lap Sealant applied

Adding in some select Pine strips as a backer to the fan base screws. These boards will also become anchor points for my ceiling panels.

And Dicor lap sealant added to the fan bases as an extra layer of waterproof protection.

Now enjoy your new fans and the added space up top!

2 comments

  1. Great write up. Very helpful. I am about to tackle this project. Just wondering if you did anything in the engine compartment. I have read how others disabled the ac pump by installing a smaller belt that does not drive the ac pump pulley. Just wondering what you did. Thanks!

    Like

    1. Hi Keith. For now I still have the compressor in place and I’m running the stock belt, but like you mentioned eventually I’ll pull the compressor and install the smaller belt in its place. Concentrating on the interior build at the moment :-).

      If you have any questions on the project just let me know and I’d be happy to help out.

      Hodakaguy

      Like

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