I was installing a new HU in my 2004 C230SC and I couldn't find an ACC power line (+12V that comes on when the car is turned on). I checked all pins against the ground with a multimeter and the constant +12V was the only one I could find. I ended up canabalizing my cigarette lighter to get the ACC power, but I'm curious if there is another solution, as I haven't found any complaints about this in the forums, and I'd like to have my cig lighter back to inflate my emergency tire if I need it.

Thanks in advance.

 

Hi,
what you found out, is correct. There is no Acc Power Line (terminal 15R) in your car. The stock head units get there signal via CAN-B. So you can just use a cable splice to get your cig lighter back to life! Be aware the fuse for your cig lighter is a 15A fuse.

 

15amps is more than enough to run both of those...Acc wire needs only a small current to trip the relay in the radio, the power comes from constant cable not ACC

 

@55fanatic,
that's what I was talking about! Of course the headunit just needs a few mA, but if you install the wire, be sure to have a wire with a diameter which fits for the 15A-Fuse!
When using just a very thin wire ("I just need the ACC power with a few Milli Amps"), and then there is a short circuit of your thin wire against ground, you will have a pretty "hot wire" or even a burning car! For this reason, for the ACC signal you should use a wire which has the same diameter as the wire leading to the cigarette lighter.
Greetz from Germany.

 

Im having areal nightmare trying to get my AVIC-X1 working - just need a bloody ACC cable and I know theres one in the cigarette lighter but which cable is it - what colour etc?