95 C280 A/C Blower doesn't shut off
 

1995 C280. The A/C system blower seems OK in the auto mode. Seems. So far I can't confirm that 100%. However, if the system is running in the "auto" mode and I press the "0" button, the blower should shut off, but it doesn't. Also, after I shut the key off, the blower continues to run for 3-5 seconds, then I hear a click and the blower shuts down. This car has the older system with three groups of buttons (similar in appearance to a W140 S-Class). Any ideas? Also, can this system reveal diagnostic codes the way the later sysytems can? If so, what is the procedure?

Do a search on C280 AC there are several threads that give the code sequence for the AC.