any webasto guru out there

[rumb]

Like any other part of the 6.9 this is going painfully slow.  I have tested and fixed each component of the system, yet it still only begins the first steps of startup.

I am planning on removing the system and putting on a workstation board so that I can more easily access each component and build a manual set of switches to simulate each step that the controllers does. At this moment I am suspecting that some or one of the thermostats or fuse links are not working.  If they are not, then finding parts will be extremely difficult, though I am bidding on a 24V unit on ebay currently that I can rob a few parts from. 

Another option  is I found a brand new unit, but unfortunately 24V so it would require voltage converters to be installed in my system. most of the electrical parts are different between the 12V and 24v models.

Still I persist!

start up sequence attached

[s class]

Awesome.  I admire your tenacity with this.  I hope you do get it sorted. 

[daantjie]

Hope you are keeping a fire extinguisher handy for all these shenanigans

[rumb]

After studying the wiring diagram and startup process I deduced that the thermo fuse was blown, thus leaving open the circuits that allow the 2nd step of startup, those being the fule pump and the air blower.   I was worried that this would be some unobtanium part, yet I am please to find out it is a very common electrical component.

Thermo fuse NTE 8139

Attached are pictures of the original and the replacement part.  you may notice that someone has already replaced the little thermo fuse before. You just solder one end onto the wire and cut the other lead off!

Parts (with extras ordered)

[rumb]

deleted duplicate post

[floyd111]

Please keep the reports coming. there is very little out there on the webasto's, so it's pretty important stuff, me thinks.
BTW, would the thick blue "Sonderausstattungen" book be helpful here?

[rumb]

Just found purchased a WP1021 spared parts manual from somewhere in Finland.  Will copy in  few weeks when it gets here.

As old as these are, EPC and Mercedes part numbers are useless as all parts are NLA.

[rumb]

Just received Webasto parts manual. Part numbers no very useful as searches only found one part in Russia available. But good to see breakdown of unit.

getting close, but fuel atomizing chamber I cannot seem to get working. I may have just purchased a complete 24V unit that I can take that part out of. but most electrical parts are not compatible with my 12V unit.  will probably resell once I get what I need.

[floyd111]