Eberspacher D2 wiring (1 Viewer)

[Gadget Man]

Amongst the many, many things to do is fit a PSU to my monster build to run the night heater off shore power or solar battery via selector switch.
This would be simple, if it were not for the coach built nature of the wiring loom running from a second fuse panel that powers both the D2 and an AC unit. I am looking at what I think are the power wires on the end of the original loom, but am not entirely sure.
There is a combined climate control box.
A temperature probe for each function.
Need to be certain of the wiring color code.
Maybe two separate control units?
Rather than blow something up, I thought I would ask to see if anyone knows better.
I would like to power the AC in a similar way with a PSU, eventually. Probably a lot of amps. I don't want to power up AC accidentally from the 10A 12v PSU for heater. The priority here is the heater. A way to switch between engine 12v and shore power 12v PSU would be great.
Quite a few relays here. The one on the far left appears to be ignition activated.
I'll post a picture later, if that helps.

 

[Gadget Man]

What I have found so far in a video, is that a yellow wire is the control wire for signal/power on.
The connector marked D2 is what I think is the Eber source - +, The orange/white and brown wire look heavy enough to be this.
It looks like the supply is fused before the Eber and AC.
I guess that the majority of the relays are for AC.