i have a 1994 mercedes e320 sedan .my car just started doing this the other day.. randomly when i get in my car and start it the air recirculation switch light blinks really fast and i hear a clicking behind the dash along with it,.. it does this for about 2 minuites then stops.. once it stops sometimes the heater controls work and sometimes they dont .. can anyone help me figure out what is wrong and is this a common problem on my car.. im guessing there is a control box behind the dash that is tweaking out or something.. any help would be appreciated.. thankyou