It finally got cool enough I noticed our E320 seems to have some heat, but not full, from the dash vents most of the time regardless of the temp wheel position. I've caught it behaving normally a few times, and the air outlet seems to change normally depending on the temp wheel position, it just stays a bit warm on full cold. Which might be part of my marginal AC performance all summer
. Any diag to be done on this thing or just start replacing likely suspects? It seems to work as it should otherwise, I replaced the sample motor last spring.