What causes the shaking of a Mercedes-Benz at idle with the air conditioning on?

[Lincoln]

Mercedes-Benz shaking at idle with the air conditioning on is caused by the air conditioning not speeding up and excessive compressor pressure. Air conditioning not speeding up: Generally, a car's idle speed is maintained at around 800 rpm. If the air conditioning is turned on, the idle speed should normally increase accordingly, usually maintaining above 1000 rpm to avoid shaking at idle. This speed increase is mainly controlled by the computer via the throttle. If the idle speed does not increase when the air conditioning is turned on, the throttle should be cleaned and then recalibrated. Excessive compressor pressure: Excessive air conditioning pressure increases the engine load, causing shaking. Generally, poor condenser cooling, excessive refrigerant, or dirty air conditioning pipes can lead to excessive pressure, indirectly causing shaking.