Minor progress on this today thanks to Ian (IT) pointing out (in my DVB-T thread) that the reversing light signal is fed to the RNS-D - it's labelled as RFLS (Rückfahrlichtschalter). ;)

So I fixed up a feed from that to the drivers footwell area and it's now powering the video interface box.

The next step is to fit the radio link for the camera. Hopefully the ski hatch will let enough signal through.
The receiver end is very easy as I've put an extra connector on the new feed from the RNS specifically for it.
The transmitter end means taking the boot lid apart again and a little bit of wiring, definitely a job for another day.

When I start fitting the DVB-T tuner there will be some minor changes to keep the camera working properly. All around the drivers footwell.

Today in fact. :D
All installed and working and the cable running the length of the car has been removed.

I managed to install the transmitter in exactly the wrong place first time - it prevented the warning triangle being put in the boot lid. Just needed moving an inch or so. Receiver is above the fuse panel by the drivers feet.

The only (minor) future change will be when the DVB-T tuner is installed, a relay will automatically "flip" the video signal between TV tuner and reversing camera when reverse gear is selected. :cool:

Another job well done Andrew.

Wish I had your enthusiasm at times to do this sort of thing. Took me a year to do the auto-dimming mirror, and there is stuff I bought two years ago that I haven't fitted yet :-(

Honestly Sean, I take even longer than you, I just get occasional bursts of energy!
The TV has been lurking around from the old S8 which had an analogue tuner from the factory, and I've had this S8 for over 4 years now!
Similarly the XCarlink was in the old car and only occasionally in this one.

The camera was the spur, I decided I really wanted one and once I started looking at wiring, power supplies, mounting etc. it all started falling into place.

I have loads and loads of incomplete projects, mostly nothing to do with cars; I pick up the one that takes my fancy when I'm in the mood. Extending the house forwards over an underground 3-car garage is still on the list....

So there's hope for me yet then :ROFL:

Wonder how long it'll take me to do the solar sunroof :rolleyes:

Just for completeness here's a picture taken this morning.

The Audi bumper is just in view and the Volvo is about 10cm away, it's front parking sensors are brilliantly accurate (no front camera) and I parked it there easily and quickly last night.

And that actually arrived today, a standard 20A 12V Micro Changeover relay. :cool:
This evening I worked out what was needed to link it in, found all the bits I needed in my piles of old cabling and constructed a loom for it.

Five wires on the relay: Power/ground, TV-in (RCA/phono plug), video-out (RCA/phono plug) and camera in (RCA/phono socket). The three video leads have all the screens connected together as well.

There's a bit of work on the car, related to the TV tuner, to rejig some power leads; when that's done this will plug straight in. Not yet as its default setting is TV rather than reversing camera and only the latter works properly at present. :o

All done apart from tidying up the wiring (though the tuner has an intermittent fault so will be replaced in due course).

Particularly satisfying to be tuned to Radio 4 at startup (my default mode) but now via the DVB-T tuner and then have the reversing camera video switch in automatically while the radio sound stays on. +++

Who says you can't switch a reversing camera on automatically when you have an RNS-D. :tuttut: (limitations apply :ROFL: )

Replacement tuner has arrived and I have discovered (as noted in the DVB-T thread) that it appears to be designed to switch to an AV input (from a reversing camera) when triggered by a +12v signal from the reversing lights.
Should be fairly easy to connect that up and simplify what I have at present as I happen to have the correct video input lead already (not supplied with it). :cool:

Edit: Tested but abandoned as an idea: it also switches sound input (non-existent from the reversing camera!) :tuttut: so I'm sticking with my external relay to just switch video over and keep radio/TV sound on.

A longish messy thread, so here is:
Summary of a reversing camera installation - in a car WITHOUT OEM TV.

Camera from eBay/China, 45 degree downwards type, is mounted centrally immediately above numberpate on boot lid. It is almost totally hidden by the numberplate surround when this is refitted.
Plastic numberplate mount removed and hole cut to fit round camera; camera is fixed to metal of boot lid using rubber well nuts to avoid corrison issues.
Camera is mounted on a rubber backing plate which both provides a weather seal and allows slight adjustment. Final position just shows the rear bumper at the very bottom of the screen.
Radio link from camera mounted inside boot lid behind trim sends video to receiver near driver, presumably helped by my car having a ski hatch. It and camera are powered from the reversing light circuit which is easily accessed with the trim removed near either reversing light.
The radio sender I bought provides a power output to the camera so wiring them both in is very simple indeed.
Reversing lights had already been replaced with LEDs so plenty of spare capacity in the circuit.

Radio receiver and T-ERA video interface (now NLA but there are alternatives) to RNS-D mounted in drivers footwell behind knee panel.
Power supplied from RNS-D circuitry and relay(s) using the following sources:
1. Permanent 12V from RNS to CD changer.
2. Switched 12V (CD changer circuit) activated whenever RNS is on.
3. Reversing light power available at RNS (actually in the same circuit as in boot lid)

When RNS is on #2 triggers a relay to send power from #1 to the video interface via a fused lead.
(This supply is also used for the DVB-T tuner, without this option the video interface could simply use the same supply as the radio receiver)
When Reverse is selected #3 supplies power directly to the radio receiver.
(The same circuit also activates the camera and transmitter in the boot lid)

With DVB-T installed a second relay is used, triggered by #3, to switch the CVBS signal to the video interface between DVB-T and camera.
The DVB-T sound is connected at all times so that audio (TV or radio) is maintained when reversing.
If you are not using (or don't have) the DVB-T you would need to select TV input on the RNS-D after selecting reverse.

And recalling my "objectives" from post #1:1. Achieved +++ (mounted centrally above number plate)
2. Achieved +++ (in conjunction with DVB-T tuner)
3. Achieved +++ (Digital TV added, new dual diversity tuner)
4. Achieved +++ (after some tricky wiring repairs, both camera and DVB-T use this)
5. Achieved +++ (bought a Kufatec loom, adapter option doesn't work with RNS-D).