the ignition well not turn on my 98 merecedes benz clk

SEEK HELP FROM A MECH IT COULDB BE SEVERAL ISSUES INCL STARTER

Had this problem a lot of times, even had a new ignition/key installed ($1,200); however, still had the problem, 2 other times. Had the car towed to Mercedes dealership and a Mercedes cert shop - both times they told me it was the starter (2 new starters within 2 years.) Found that it is the alarm, thinking it is being broken into, cutting off the ignition. And when this problem occurred, I would push on the brake (sometimes pumping it) and tried moving the gear-shifter from P to D - something in the ignition/brake/gear-shifter. Hard to explain, but it has solved my problem after countless visits to the dealership?!