Just for the records and future reference.
I've edited post as resolved.
And give a nod to @Deaky in the start that asked about any modifications, whether relevent or not.
At the time it was assumed the retrofit MFSW and PDC were not relevant.
But in reality were a route cause of the symptoms.
So once again going back to basics with electrical fault finding..... Always disconnect any 3rd party or add-ons before diving deep into the vans systems - to rule out any iffy stuff.
Glad we got to the bottom of it and to can get back to enjoying your van.
.
.
I've edited post as resolved.
And give a nod to @Deaky in the start that asked about any modifications, whether relevent or not.
At the time it was assumed the retrofit MFSW and PDC were not relevant.
But in reality were a route cause of the symptoms.
So once again going back to basics with electrical fault finding..... Always disconnect any 3rd party or add-ons before diving deep into the vans systems - to rule out any iffy stuff.
Glad we got to the bottom of it and to can get back to enjoying your van.
.
.