Like others, I was the victim of the HVAC Fan Blower Resistor Regulator. Thanks to to great video and owner posts, I replaced the Regulator and Cabin Air Filter for $44.37 (delivered) in less than 20 minutes. I used the MB part cross reference and ordered the Regulator on eBay. The replacement Regulator I chose came with a 10 year warranty and cost $27.39. This is my happy face!