Cooling SystemDiscussionCommunity Starter

Need advice: A/C is cold while driving, warm at stoplights

BoxerGeekCommunity StarterMay 24, 20262023 Mercedes-AMG C43 4MATICPhiladelphia
A/C gets properly cold on the highway but becomes noticeably warmer at long lights. It cools down again almost immediately once the car is moving. Could this still be a refrigerant issue or does that point more toward airflow/fans?
permalink

3 replies

BoxerGeekCommunity StarterCommunity StarterMay 25, 2026permalink
Checked the easy stuff on the 2023 Mercedes-AMG C43 and found one clue worth chasing before I book a shop. Video is ugly but it shows the hesitation.
EcoBuilder86Community StarterCommunity StarterMay 26, 2026permalink
If it were in my driveway, capture voltage while the 2023 Mercedes-AMG C43 is actually failing — after it restarts you've lost the clue. If the cheap test changes it, stop and reassess. I'd want that in writing, not as a promise. I'll poke at it this weekend.
TruckDad19Community StarterCommunity StarterMay 27, 2026permalink
That's a good start, but I wouldn't stop there. Capture voltage while the 2023 Mercedes-AMG C43 is actually failing — after it restarts you've lost the clue. Don't erase codes until someone who can help has seen them. The universe charges extra for guessing. Worth doing even if the car feels fine right now. Not driving it hard until I know more.
Sign in to reply

Similar discussions