Jaab

Doe3s anyone know what line is going to give me my accessory turn on 12v? I have the 12v constant, the ground as well, but I am missing the 12v switched to the ignition. Any help would be great, I have totally stripped my old 04 SL500 and I am in the midst of doing a stereo upgrade. Thanks to all!!

latemodel21

Some "CAN adapters" will extract the "12v switched" from your can bus.


if you are not using one with that functionality, you can go old school and....
Find a "Circuit 15R" wire and use it to control a relay (and then source the power from your "constant" source).

you will find "Circuit 15R" at pin 4 of your N73 module and pin 2 of conn 1 on the K40/2 module.
Cheers,
Chris

Jaab

chris, excuse my idiocy, but what/where is the K40/2 module? also, can I go an even simpler route and pull an acc 12v from my cigarette lighter??

latemodel21

The K40/2 is in the small compartment just inboard of your driver's side hood hinge (between your ECU and the brake master cylinder).

My first thought was to suggest that the cigarette lighter might be a simple solution ... however, I seem to recall (at least on a 2003 SL55) that the cigarette lighter gets its power cut when you have a "consumers offline" situation (consumer/trunk battery is low ... which happens when the car sits for as little as 4 days unused). I can't imagine you'd want to be without your radio under those circumstances ... and I DON'T think the "circuit 15r" line gets similarly disabled.

Cheers,
Chris


oops, forgot the ... what is the k40/2 ? question
it is the Driver-side fuse and relay module (SAM)