Hi,
I'd leave it as is short term, bearing in mind your test you did :wink:
I'm gonna go out on a limb here .....................
Disclaimer :- I have never dabbled with a 32, and as said, I'm no ICE Expert .........................
but ...........................
Some, well, a lot of MB's I work on including my own S 55, my mates CL 600 which are similar vintage, plus Mels C Class which is newer, they have a wiring system that works over the Body CAN (no Acc wire) on their standard MB COMAND set up .........................
When you switch off ignition, the Stereo stays playing until one of these 3 scenarios .......................
1) Battery Voltage gets below a preset value
2) A time period, (half hour IIRC elapses)
3) You open the Drivers Door
....................... At which point the Unit powers down, switches off etc etc ....................
So perhaps the SLK 32 was Wired this way ????
If you give me your VIN I'll have a look at some point on MB WIS Wiring Diagrams to see if it is wired any different to my own 2002 SLK 320 V6 Car.
On that note, I was actually thinking of putting a 20 minute timer relay in the Acc + circuit on my SLK, because the Android has a long boot time, (that's their only disadvantage as far as I can see and we have 3 of them in our Cars, the C Class and S Class both work on Body CAN and boot up quicker, but the R170 has not got a suitable CAN, that's why I had to hard wire everything, but I simply used the Cars existing Batt+ and Acc + that the Car had at it's Plug) ....................
So for my R170 example if I re fuel, I switch off Engine, Android powers down, come out of paying for fuel and drive off, it takes a period to all boot up again, about twice sa long as the other 2 Cars, so a timer relay would leave it running, and I could just hit the pause or mute as I got outta the Car .......................
Now I confess, I'm going to check all the many settings Menus, because there may be a "Delay Shut Down" option or "Sleep Mode" rather than "Power Down" in one of the many many settings I've not played with yet lol ......................
Yeah, it would be really hilarious if I wired up and installed a Timer Relay etc only to find the H/U will do that anyway :biglaugh: So best I have a good look first eh :wink:
HTH, Cheers Dave