E320 CDi - Electric cooling fan not being activated by air con

[chopperovski]

Hi

I have a 2005 E320 Cdi Estate (S211 in line 6 engine)

The cooling fan does not run when the air con is on but it does run at other times such as when car stopped in traffic.



Today I disconnected what I think is the aircon pressure sensor and the fan started to run at high speed. I have previously had the fault code p1636 - Engine AC electric suction fan signal wire open circuit.

Does all this necessarily mean that the sensor is faulty (it does look as if water might have got down there) and if so can it be replaced without having the whole system recharged?

Thanks

 

[LostKiwi]

Disconnecting the sensor will make the fan run at high speed. A bad sensor or low pressure likewise.
The fan will run when needed - it doesn't need to run all the time the Aircon is on.

 

[chopperovski]

Thanks LK - but I'm left wondering what the p1636 fault code meant. It was listed as "permanent" and something must have caused it.

Also probably should have said in original post that air con isn't very cold despite being recently regassed