Espar high altitude compensation

[Fitz]

If you look at page 12 of the attachment found in Post 525 you will see a schematic diagram that contains the high altitude unit. Shown are the colors of the wires that you are interested in: red, yellow and blue/white. Happy searching!

[LarryB]

I have red, yellow, blue and white wires (among others) but no blue/white wire (assuming that means blue with a white stripe). Below is a photo (I hope it shows up) of the wires on the back of the panel.


I was able to use a mirror and flashlight to see what I believe is the altimeter box in that compartment, attached to the front wall part way down towards the bottom from the control panel opening. Hope I never have to actually access it!

[drobinson]

On our build (2018 Texas) it is installed behind the control panel as mentioned above.

[LarryB]

Well, that's three of us that have seen it behind that control panel so I guess it is/was the standard place of installation. Why, I have no idea. It makes no sense unless there's a high probability that access will never be needed.



I'm still wondering about the existence of the fuse for the altimeter that Michael Rixen mentioned. I guess I won't worry about that unless I need to because it may well be behind that panel along with the altimeter.

[1der]

What I do not understand is why there would be a fuse in the Hiigh Altitude Sensor circuit? When I installed mine the HA harness did not have a provision for an inline fuse.

Maybe an SMB thang?

[LarryB]

Well, it could be a Sportsmobile thing or, perhaps more likely, I may be misremembering what fuse Michael was talking about!

[FarmHand357]

Larry/Fitz, much appreciation for posting this valuable info. We have a SMB Sprinter build from early 2021. I too had read of the importance of running the diesel burner flat out for 15 minutes or so before shutting it off to burn off potential soot deposits and prolong the life of the screen.

When I contacted Jim Rixen with a separate question and inquired about doing this, he said that the newer systems (which all also include the high-altitude kit, I believe) run the glow plugs both before starting and after the thermostat cycles off, and that this helps prevent the buildup significantly. He said they had a test bed with multi-thousand hours and no rebuild still going strong. I have noticed that my overhead lights flicker both when the system is starting and after it cycles off or is totally shut down when in the diesel mode.

Fitz, does any of this jibe with your research? We still run ours steadily before a final shutdown in the hope of maximizing time before a rebuild, but are wondering if this is less necessary now...? Thanks for any info in advance!

[Fitz]

FarmHand357,

You reference "the newer systems". Any idea when "old" transitioned to "new"? I'm guessing mine is an "old" system.

My 2016 unit has been serviced once early on (2017?, I don't recall off the top of my head) with no further service since running the unit monthly and for 15 minutes after every use. The other thing I do is to listen for the ticking sound the fuel delivery pump makes. The pump cycles, thus I do NOT turn the heater off until the ticking stops.

[FarmHand357]

Fitz, much appreciation for your quick response. I don't know when there was a transition; I looked at your big file and noticed the controller looks different than mine:


Thanks also for the info about the fuel pump; is it located outside the van near the fuel tank or or by the actual Espar unit?

[FarmHand357]

Had difficulty attaching a pic: