Hello! Have a Ducato 2,8 jtd 02 with Dethleff motorhome. When driving, speedometer suddenly stopped working and motorlamp on. Workshop replaced speedsensor but no response. Got speedometer wiring diagram and found that fuse F11 12v going to speed sensor K084 was blown. The wire connects also to E5030 and E5050. Tried to replace the fuse but no, it blowed. Must be a shortcircuit to ground on the wire or in E5030/E5050. I dont know what these items are.
Hope someone can tell me..

Oops

...read all of this thread:

https://www.fiatforum.com/ducato/277758-fiat-ducato-2-8jtd-motorhome-fault-codes.html

Fuse F11, designated secondary services, supplies among other items the oil vapour heater. This unit is known for developing short circuits, and hence blowing the fuse.

I consider that this is the first item to eliminate. The oil vapour heater is situated behind the radiator, and above the starter motor. See picture taken from underneath vehicle.

Unplug the heater to confirm diagnosis. Please note that my engine has only one heater, but eLearn shows two separate connectors in parallel. If two heaters are fitted the will be side by side, and you may have to disconnect both.

You will be OK to run without the heater when outside temperature is above freezing, but Norwegian winters could necessitate replacement.

I am adding this after posting. I have just noticed the mention of E5030 and E5050. I cannot trace E5030, but E5050 is the engine management. See link below. The "star" of wires at the lower section of the diagram are all assosiated with F11.

http://4cardata.info/elearn/244/2/244000001/244000003/244000005/244002482

Tanks for hints so far, I will look them trough and check them out..

Hello! I did disconnect the contact and put a new fuse in and started the engine, stopped and pulled it out and the fuse was not blown. Have to take a testdrive tomorrow and erase the failure codes which all indicated shortcirciut.. Thanks..

For the record, eLearn diagram E5030 mentioned above, relates to the engine management system for the 2.0 litre petrol / gasoline / benzine. engine.

Hello again! Took a testdrive yesterday and speedometer is working again, and the glowplug lamp is not blinking any longer. Tried to google this "oil vapor heating resistanse" part but can`t find it anywhere under that name. So, is it possible to get this part outside the Fiat Part system. I do appreciate all the help I have got in this tread..

Following link is a possibility. Check compatability.

https://coastalmotorhomes.co.uk/fia...y-2-8l-jtd-hdi-blow-by-pipe-hose-1421-e8.html

It looks very simular to my version. Have to disassemble it tomorrow and see closely and then I hope it will be the end of this story... So once again, thanks for all help.