Said It Here

Why is my car AC blowing warm air and stuck on the wrong vents?

Car air conditioning faults often stem from failing components like a wobbly AC clutch or blend door issues that misdirect airflow. These problems leave drivers wondering whether they need to replace the entire compressor or just individual parts like the pulley and clutch.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    scanning for fault codes using VCDS
  2. 2
    attempting to recalibrate ventilation positioning motors via diagnostic software
  3. 3
    replacing pressure sensors or faulty ventilation motors
  4. 4
    Replacing only the clutch or pulley assembly rather than the entire compressor
  5. 5
    Inspecting and listening for noise changes when the AC is toggled on and off

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/MechanicAdvice2 people · September 2026

“my 2004 vw golf mk5 2L diesel doesn’t blow cold air, and it doesn’t go trough the vents it should. These are the faults i found on my vcds, is this a expensive repair???”source ↗

HighlightChance6113 · r/MechanicAdvice · 1 upvotes

“Started hearing intermittent chattering/light squeaking on cold starts the past few days. Popped the hood and just noticed my AC Clutch looks wobbly when the AC is running.”source ↗

Byrns149 · r/MechanicAdvice · 1 upvotes

“Would this require changing the entire compressor or just the clutch/pulley?”source ↗

Byrns149 · r/MechanicAdvice · 1 upvotes

Where this came up

People with this problem also raised