Magnetic Clutch Control: Climate Applications

Hi there,

I have a Sharan from '98 with manual air conditioning. When I turn on the AC, the indicator light comes on and the fan for the condenser starts running, but the magnetic clutch is not being activated.

Question:

Are there any locking mechanisms in the manual system?
How does the switching signal from the switch reach the compressor (via a relay or similar device)?

Does anyone have a circuit diagram?


Thank you in advance.

BERT.

Hi Bert,

The air conditioning compressor is activated via a relay. For this to happen, the internal pressure of the system and several other conditions must be met.
I've heard several times from Sharan owners that the condenser fails, causing the refrigerant to leak out. Then, the cooling system stops working! By the way, the Sharan has (in my opinion) a much too small air conditioning system for a car. Newer models have a different AC system designed to avoid such failures.

Hi there,

Okay, thank you so far. I've traced the lines and only found a sensor on the collection tank. Does this sensor need to be open or closed for sufficient minimum pressure?
Hintergrund: Die Anlage war schon mal Leck. Damals funktionierte aber die Magnetkupplung weiterhin obgleich keine Kühlleistung erbracht wurde. Bevor ich nun wieder Euronen für ne Testbefüllung investiere möchte ich einen el. DefIt is not possible to exclude this.

P.S.: How do you actually lower the relay panel on this vehicle with a quality defect?


best regards

BERT.

Hi,
Okay, so if you're referring to the dryer's lint trap when you say 'collection container,' and if that sensor there has a 4-pin connector, then it matches the description I posted in another thread a few days ago.

The pressure switch activates when the system pressure is too high or too low (normally open contact; first contact pair), AND a second contact pair (normally closed contact) turns on the cooler fan one level higher when the system pressure exceeds 16 bar.


I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Andy.

Hi there,

'Yes, I have the 4-pin connector. However, to measure the pressure sensor, you would need to disassemble about half of the car (Sharan!). Does anyone know where the signal indicating 'PRESSURE WITHIN NORMAL RANGE' needs to be reconnected? Is it on a relay panel, at a specific relay number, or somewhere else?'


Best regards,