Mercedes W203 HVAC climate control system explained AC Clicking & Hissing Noisy AC Flaps Actuator

IMPORTANT!!! (PRESS SHOW MORE) see bellow (Especially for M2/15 left/right footwell flap stepper motor and/or lever replacement)
Mercedes W203 463 HVAC climate control system explained
• Identify the climate control system used on W203 & 463
• Locate climate control components and serviceable items
• Describe the function of climate control systems and related components
AC clicking sound issue / Noisy Air Conditioner / Stepper Motor Replacement / Clicking & Hissing

IMPORTANT!!! (Especially for M2/15 left/right footwell flap stepper motor and/or lever replacement)
If you attempt to FIX your problem(s) (replacement stepper motors/plastic parts: lever, etc.) to make your life much, much easier buy a TORX SCREWDRIVER (T20) long or regular length. You need a screwdriver NOT a bit on universal tool because of the thickness of the tool. If you can do it, magnetize the torx screwdriver tip.
Some of the tools used:
10mm socket
ratchet (preferably 3/8")
6-12" extension (for ratchet)
T35 Torx socket (3/8")
T20 torx screwdriver
plastic wedge
Some part numbers:
A2038300033 Operating Parts Kit
A2038300233 Operating Lever Right
A2038300133 Operating Lever Left
A2038300032 Linkage – Parts Kit, Footwell flaps without operating lever
A2038201642 Stepper Motor / flap positioning motor (all same)
A2308216351 Blower Regulator
Item 330 A2038202514 Electric Motor