problem with the air conditioner. Will not maintain a cold condition. on 2000 Mercedes-Benz S430

Air only comes through the center vent. The blower is very loud but does not cool the csr.

Asked by for the 2000 Mercedes-Benz S430
make sure cabin air 'dust' filters are clean.. use 'auto' and make sure side vents are not closed other than that i would have to see what MB diagnosis codes were stored.. but first of all i would disconnect battery for 1 min then reattach and see if system fixed itself.. ( dont laugh it has fixed many 00 and later MB's for me)