Sprinter Van Heater Install – Part 5

Here we’ll walk thru the process of hooking up your electrical for the install of your diesel powered Espar D2 / Airtronic D2 heating unit in a Sprinter Van or RV.  Remember to refer to your installation guide from Espar at all times.

Step 15 – Mount Controller

Pick your mounting location. In my case, I opted to mount it where both I could reach it as the driver, and where my second row passengers could reach it, while still being far enough from the heater unit itself to not immediately register warmer heat than if it was directly above the heater unit. I mounted it below the seat belt assembly beside the driver seat. The plastic panel is easily removed – it uses metal clips imbedded into the plastic to connect it to the wall. Wires can be easily routed between that plastic panel and the wall.

Step 16 – Route Wires

Now it’s time to route those wires from the passenger seat, under the floor (there’s a little tunnel under the rubber matt for routing wires, and then thru the drivers seat base, then up the wall to the controller unit. Hookup is described in the user manual. You have to decide if you want to use the thermostat in the controller or the one in the heater. We opted to use the one in the thermostat so we connected that wire. There have been mixed reviews of this setup, but it’s too early for us to comment on its effectivity. Check back, and we’ll update this post as we have more experience with the setup.

You’ll also need to route the fuel pump wiring harness down thru the rubber pass-thru hole in the floor and connect it to the fuel pump. This ensures the fuel pump receives the signal from the heater unit to send fuel when it’s needed. The rubber pass-thru is a brilliant setup that makes this step easy. Thank you, Mercedes Benz.

Step 17 – Attach Ground and Power Wire

Now it’s time to attach your ground wire to either the grounding screw in the floor of the driver seat base, or to create a new ground. I opted for a new ground but I expect to change that in the future. We’ll show you a photo of our new ground screw, but I recommend using the existing ground screw of making your own. Once the ground is installed, then move on to secure the hot wire as shown. Note that this location provides constant power whether the key is in the ignition, or the vehicle is running. The other two spots are options but will require the key to be in place, or the vehicle to be running.

Step 18 – Test It

Ok, now the last thing to do is to fire it up by turning the controller switch to the one position. Look for the red light. Once on, adjust the temperature wheel to fire up the unit. Watch and listen for the unit to fire up, heat to start blowing out of the vent hose, and for exhaust to start coming out of the exhaust hose. Now go enjoy a cold beer.

Part 4 – Fuel Hookup

References and Resources

The following items were used as reference materials and resources during the install process. These are the official documents from Espar, and we recommend adhering to these whenever possible or whenever there are questions.

Airtronic Heaters Installation Guide

Ken Clark
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