02 C240

My 2002 C240 climate controls work well. I get heat and cold in all vents. However, for months I've been searching forums for this particular problem.

Excessive heat builds up in the driver's foot well area. Heat builds up when I drive (esp. warmer weather) and when the heat or A/C is on in top vents only. The plastic panel below the dash and above the feet starts getting hot and then heat starts seeping in the right foot well vent. I don't mind so much in the winter but in warmer weather, it's uncomfortable.

When I take the plastic panel off, I can feel the heat blowing from the center console/evaporator core area, especially when climate is on or driving. As I start and stop the car during the course of the day after short trips heat also builds up. There was only one time driving the heat didn't develop and the plastic panel was cool to the touch. That was when I drove on the highway at high speed in cool weather nonstop for at least an hour..

Any input is much appreciated?

Rudeney

Welcome to the forum! Try the ACC test/reset procedure: With the engine running and in park, simultaneously press and hold the FRONT DEFOG and RECIRCULATE buttons. Continue holding them pressed in until their indicator lights begin to blink, then release them. For the next 20-30 seconds, the ACC system will test and recalibrate all of the damper servos. If all goes well, the process stops and the lights stop blinking. If there is a problem, the test will just continue to run until you shut off the ignition switch. If there is an error, you need to pull codes using an MBZ-specific scan tool.

02 C240

Thank you Rudeney. I tried the ACC test/reset a few times actually. Lights stop blinking after about 30 seconds and no issues with the ACC system. I get hot/cold air in all vents.

It’s the heat that seeps into the cabin. Maybe hot air leaking in through firewall, from evaporator core, or heater core? Wonder if anyone has experienced that and what the fix was?