Got the most annoying clickin noise when i start the engine comin from the dash It then goes after about 15 clicks...... Wot the hell is goin on??

 

The plastic linkage to one of the A/C stepper motors is broken. Most common is the footwell flap step motor. The part is cheep, but the labor is not!

 

So if my step motor under the dash is gone can I fix it myself

 

You "can", but it would probably be a lot easier on your soul to have an indy that's done it before tackle it.

Or, go for it. You'll probably have to search a few mercedes forums websites to find detailed instructions.