Possible Concerns
The A/C system is functioning correctly when the air flowing from the instrument panel vents has a temperature of 7 °C (44.6 °F) or lower.
Setting on Climatronic "LO".
Setting on A/C system "AC" on; "max" ; "cold".
With all complaints marked with *. Refer to PRESSURES, CHECKING .
- Total cooling system failure. *
- Insufficient cooling performance at all vehicles speeds or engine speeds. *
- None or insufficient cooling after driving a few miles. *
- A/C compressor, A/C Clutch -N25- or A/C Compressor Regulator Valve -N280- are switched off by A/C Refrigerant Low Pressure Switch -F73-, A/C Refrigerant High Pressure Switch -F118-, A/C Pressure Switch -F129- or by A/C Control Head -E87- or Climatronic Control Module -J255- due to excessive or insufficient pressure. *
- None or sharp decrease in fresh-air supply after driving several miles (evaporator iced up). *
From these, the following complaints may also occur:
The A/C Compressor Makes Noises
-- Re-tighten compressor securing bolts and compressor bracket using a torque wrench.
-- Check routing of refrigerant lines; they must not touch other components and must not be subject to strain (align if necessary).
Noise (Refrigerant Hammer) Occurring Immediately after Switching on Air Conditioner and/or When Cornering or Braking:
-- Discharge, evacuate and charge refrigerant circuit (too much refrigerant in circuit).
Too much refrigerant oil in the circuit could also cause this problem. This could occur if the amount of refrigerant oil was not adjusted when replacing the A/C compressor. If this occurs, flush the refrigerant circuit with refrigerant R134a. Refer to REFRIGERANT CIRCUIT, FLUSHING WITH R134A REFRIGERANT .
Drain the refrigerant from the A/C compressor. To facilitate this, the ribbed belt pulley or A/C clutch plate on the A/C compressor should be rotated by hand. Then the entire quantity of refrigerant oil specified by the a Vehicle-Specific Service Information should be added to the refrigerant circuit (50 grams directly in the A/C compressor).
Water Sprays out of Vents (in Dash Panel or Footwell) Although Air Conditioning System Is Otherwise Functioning Properly:
-- Check proper routing of condensate drain; it must not be crushed or kinked.
-- Check condensation drain valve, it must not be clogged by wax or underbody sealant and must open and close properly.
-- Check plenum chamber cover; it must not be damaged and must be properly installed (to stop water running into evaporator).
-- Check water drains in plenum chamber; they must not be blocked (e.g. by leaves).