So I was fiddling with my armrest, and at the back where the hinge is, there is some sort of electronics cord that enters the armrest from the center console. Now I know there is nothing electrical in the armrest, or the upper space of the armrest. Now it doesn't go into the rear a/c, just into the armrest.
Is this some sensor? I can try an post pix to see if it helps. 2005 C230K.
If the 2005 has the same armrest as the 2003, in the upper part of the armrest, on the left side of the compartment, you should see a little plastic plug. If you remove it, you should see the end of that wire. It is the cellphone pre-wiring.