10/29/2026
I'm ashamed that it took over 20 years of 190E ownership to recognize that when switching from HOT to COLD, it will take a while for the outer vent air to fully cool off since it's still blowing through a heater core full of warm water.
I kept feeling like "it just doesn't go back to ambient from the outer vents" and it wasn't until I verified the full function of the heater control valve that I recognized that the heater core will still be full of warm water for a while.
(Suction motor, temperature control panel, valve body, and heater control valve all functioning, air conditioning not functional.)