W210 aftermarket head unit help

[jimmymidnight]

I had an aftermarket DVD/iPod/everything else under the sun head unit delivered today which works on standard ISO leads, plugged it into my W210 and it beeped, but that was it...

I took it back to the store and they checked it in house and it worked fine and said it must be the wiring in the car, but no harness is available.

Is there a little trick to getting non M/B head units to work or am i missing something even simpler?

Thanks

 

[C230kompressor]

some times the yellow and red power supply's need switching round!

yellow is normaly power from ignition
and red is normaly constant 12+ for memory
iv had to switch them round befor now

 

[jaymanek]

and sometimes there is no ignition live at all so you have to nick one from somewhere.

 

[cyberflex]

All of the above, also some units I have had in the past would not come on at all without having the aerial connected aswell(another ground) worth a try, failing that, time to get a pin out for the power iso (google) and a multimeter to see if you have ignition and permanent +12v's at their respective positions within the cars power iso.Was there a working unit in there B4? Could be a blown fuse I guess.
Jon

 

[jimmymidnight]

Ok, all sorted now, turns out i needed a VW/Audi ISO harness (obviously) and now it works fine. Thanks for your help anyways!

 

[cyberflex]

Good news, I am not sure, but I think all that harness does is switch the ignition +12v and permanent +12v around, like C230kompressor was saying.
Anyways, hope you enjoy your new unit

 

[Supacool1]

Incidently which unit did you get?