I have a 2005 S250 that will not start. The key does nothing when turned. When I turn the key the hour meter does not light and the glow plug indicator does not come on, it is toitally dead. I do have power to the headlights, when I turn them on the hour meter displays. A friend tested the battery and I have a good 13 volts. When he tested there was only 2.7 at the control panel by the key. Is that correct, does anyone have any suggestions before I spend a fortune at the dealership. Does it sound like that panel itself? Thanks Mike