Got my 2000 C280 about 7 yrs ago; and it was one my best car. As it aged a few problems show up here and there. The latest one is AC related. The AC system stop working few months back - no air flow, no cold air at all. As I replaced the air blower relay and now it working fine; but this is not the end of story. The cold air only flow some of the time - it is on and off. It's either VERY COLD, or not cold at all (just blowing room temp smelly air). If it's still blowing cold air from time to time; my guess is the compressor unit still kind of functioning. But what's make it stop? Or not kick in for a while (like first 10mins of driving)? Please help!!!!