D+ Source on 2018 Fiat Ducato Based Adria Twin

[Alesupper]

Hi All, I have no voltage on my D+ cable going into my EBL208S. Does anyone know where this is fed from and also the location of the fuse? This is on a 2018 Fiat Ducato based Adria Twin. Please see attached photos. I presume that this is the D+ relay because the green wire goes to the D+ input on the EBL208S (pin 16). TIA.

 

[Jim Schush]

Just checked pin 1 and voltage is good, also checked pin 3 with engine running and again voltage good.
I am using the van for a couple of days over the weekend so I will try and work out from the schematics how to test block 1 to test if there’s any output from the EBl.
Thanks again to everyone for the advice so far.

 

[fred_jb]

Hi..
The d+ as we refer to it does not necessarily have to have a voltage present..
On a ford transit I had the d+ provided for the converter was a ground switching signal...
You could use this to power a relay coil..which in turn could then provide a 12 volt feed to power circuts which were required to be engine run actuated..
Hope I've explained that OK.
Andy

Same situation with the Fiat Ducato. The so called D+ signal is actually a connection which connects to earth when the engine is running. It's available on a connector under the B post lower panel alongside a connection which gives 12V when the ignition is switched on.

In my van the converter has used these two connections to power a relay which then activates when the D+ signal goes to earth. The relay is used to switch a 12V supply on whenever the relay activates, and it is this positive signal which is used as the D+ input to the EBL and potentially other equipment. This means that any fault finding of the D+ operation needs to include checking this relay and its connections.