Analogue to Digital TV in 2002 S8

[HPsauce]

Originally Posted by HPsauce

Though a better solution might be a switching relay driven by the reversing light to do this automatically.

And after a fair bit of thought I've decided to do this, it has a lot of advantages.

Apart from the obvious place by the light in the boot lid does anyone know of any good locations of a 12V reversing light signal inside the car that could cope with enough power to drive a relay - maybe 0.1A?

I've not yet decided where the tuner and/or switch will be located; might be in the boot side or dashboard areas depending on aerial/reception tests.

Any thoughts from anyone on the best way to get a 12V trigger signal in either/both of those areas that reverse is selected?

[notorious]

Parktronic ECU in the boot receives reversing signal so it knows when to engage.
I remember I used that wire for something, but won't remember now for what. Need checking if it is ground on reverse or 12v on reverse though.

[HPsauce]

Originally Posted by notorious

Parktronic ECU in the boot receives reversing signal so it knows when to engage.

Good point, though I think finding the wiring to the reversing light before it gets to the grommet (for the lead to the boot lid) may be easier and have a good current capacity. I think that's on the offside above the battery.

What about around the dashboard area, any thoughts anyone?

[HPsauce]

Originally Posted by HPsauce

What about around the dashboard area, any thoughts anyone?

Fuses came to mind, but sadly the drivers footwell fuse (ideal location) for the reversing lights is shared with the automatic gearbox.

[HPsauce]

Had a quick look in my Bentley manual, first challenge was terminology, eventually found the "back-up light".
Pretty simple circuit, via the F125 switch through a few connectors (around the front "somewhere") into the loom and pretty much straight to the reversing light bulbs then grounded in the boot lid.
The wires seem to be blue/red all the way from the F125 if I can find them anywhere inside the cabin!

[IT]

Originally Posted by HPsauce

Fuses came to mind, but sadly the drivers footwell fuse (ideal location) for the reversing lights is shared with the automatic gearbox.

You have an S8, which means you have factory RNS-D.

The RNS-D has a reverse wire feed so that when you are going backwards, it knows to count the gala/abs wheel pulses backwards, otherwise the navigation would be hopelessly wrong if you reversed somewhere with poor GPS reception.

Pin 17 of the 26 pin connector on the back of the RNS-D, Should be blue with a red stripe. I strongly suspect it will be labelled as such on the top of the RNS-D.

[HPsauce]

Originally Posted by IT

Pin 17 of the 26 pin connector on the back of the RNS-D, Should be blue with a red stripe. I strongly suspect it will be labelled as such on the top of the RNS-D.

Many thanks Ian, I knew someone like you would have the answer off pat.

That pin is labelled RFLS which I now know stands for Rückfahrlichtschalter (reversing light switch). I was pretty sure there was such a connection but a look at the RNS-D and online didn't show anything definite.

The blue/red wire is very evident in the loom to that connector block. I'll attack that another day.

Meanwhile over lunch today I stripped out the trim above the battery, found the cables to the boot lid and tapped into the blue/red wire there for "future use" (probably a bit of testing before the final wireless install). I did test it to confirm it was the correct one.

A bonus of removing the trim was that I got good access to the collapsing grommet on that side and glued it back together. And sorted out some other bits that were a bit "irregular".
A downside was that the cable loom was wrapped in the most disgusting gooey certoflex mess I've ever encountered. White spirit sorted that out.

[IT]

Originally Posted by HPsauce

A downside was that the cable loom was wrapped in the most disgusting gooey certoflex mess I've ever encountered.

Yes, it is a bit grim..... I'm still haunted from when I had to strip out an entire loom to get all the bits for the electric rear seat install. My fingers were a sticky black mess for days. Had no trouble picking stuff up though....

[HPsauce]

Originally Posted by HPsauce

The blue/red wire is very evident in the loom to that connector block. I'll attack that another day.

Can't be bothered to wait, worked out that this was the final bit of wiring to go behind the RNS so "set to" this afternoon.

All done, wired in new power source(s) for DVB-T and reversing camera input/relay and it's working fine (only camera at present); thanks Ian.

Just need to get the RNS fully back into place; that will need some very careful positioning of the cables as it slides in.

Then there's loads more work in the footwell to rig up the DVB-T tuner, fit the tuner/camera changeover relay (in the post!) and so on.

[HPsauce]

Originally Posted by HPsauce

Fuses came to mind, but sadly the drivers footwell fuse (ideal location) for the reversing lights is shared with the automatic gearbox.

Thinking this through, that fuse (3.6) is "probably" just for the reversing light circuit, it's connection to the gearbox being that the circuit goes through the (totally mechanical) F125 switch.
Though the connection to the RNS is much more convenient for access anyway.

It does also mention cruise control (FL so not a separate ECU ) in the drivers manual and is connected to the RNS and parking sensors in some way, presumably in all those cases for "information" purposes not power.

Given it's a 10A fuse and I now have a pair of relatively low-power LEDs in place of the original 2 * 21W reversing bulbs my little electronic additions are not going to cause a problem.
(No idea what the power consumption of the LED bulbs is, they came from AliExpress and were advertised as 50W which is clearly nonsense. Presumably that's the equivalent filament bulb so I'd guess about 5W each)