Mercedes: Mercedes CLK320, mercedes clk320, starter solenoid

Question
I have a 1999 CLK320 Cabrio.  I can open the car just fine, the electrics come on nice and bright when I turn on the ignition, however the engine will not turn over to start.  It is not a crank sensor (I think) since the engine does not crank at all. Basically the key turns to the start position but nothing happens.  I tried the spare key too. Can it be the ignition switch or the alarm circuit?  Thanks for your help,  Jan

Answer
Jan,
Have you noted any noise from the starter that sounds unusual or any hard starter under stress sounds. I would look at a blown fuse in the engine start circuit. Locate the fuse holder box and check the schematic for a starter fuse. The starter solenoid would be the next possibility.
This solenoid mounted on the starter is operated through the ignition switch.
It engages the starter to the flywheel gear, and switches the large battery wire to the starter motor. If it fails to close then you would get not starter effort.
To check the starter will require locating the main power lead to the starter motor. Because the starter is under the vehicle it would require raising the vehicle.
I would locate an independent mechanic and as them to trouble shoot the starter.

The ignition switch can also be a problem and requires considerable effort to change. I have replaced my electrical component of the ignition switch on my 420SEL and it required removal of the instrument cluster and dropping the steering column. The dealer would have charged 300.00 but I purchased the switch off EBAY for 20.00.
Good Luck
Rob