Does step retract on engine start or ignition on? (D+ = engine running, KEY+/IGN+ is when ignition is on)
How did the satellite retract before - engine running or ignition on?
(There is a difference and an extra step if D+ which makes a difference to troubleshooting)
If they all retracted etc at the same (whether D+ or IGN/KEY) its likely not a van issue its an issue - its likely a wiring issue or
fuse issue in the habitation somewhere, probably hidden away.
(We use a same D+ signal for auto step,
battery to
battery, and other bits n bobs - it will be the same signal used for all the connections)
Looking at your converters socket wiring, they have 2x red wires from the D+ so I'd *guess* your retract is on engine start . Odd they are taking 2x feeds as that' require 2x relay setups - unless they interface to something that knows D+ is 0v?
Afraid no knowledge of your conversion but would need some wire tracing to see what is where - but could be something quite simple - but you'd need to trace the wires and see what they connect to - and get a meter out and see if you are getting signals at each point. Probably trivial - but almost certainly not a van problem, so don't worry about engine/
battery etc