There are two Part No's listed for a replacement air con compressor in my Octavia II Tdi

I can see that the Sanden compressor is 1K0 820 803 S

and the current one in my car is a Zelex 1K0 820 803 N

The Zelex ones are prone to failure, but I want to only replace the clutch parts (hopefully in situ) from a 'used' compressor. Should I buy a used Zelex or can I buy the Sanden (more reliable) option and use the clutch parts from it on my Zelex compressor?

If I cannot change the parts in situ I will have to take it to a garage to fit the entire unit (de-gassing + 3hours + regassing) and would prefer to be fitting the Sanden version if possible.

Thanks,

Steve

First thing you should do is confirm it is the clutch coil as it is often something upstream. Have you removed the electrical plug for the clutch and checked the voltage?

I've also seen the wire break between the compressor connector and the actual coil - usually at the connector.

What year/engine is your car?

Thanks for the response.

MY2005 1.9Tdi PD Elegance.

Voltage is getting to the compressor and I have visually looked at the wiring from the baterry but not tested all of it. VCDS tells me it getting 1.7Nm load with the engine running but as you demand more cold it doesnt ramp up as it should, obviously the compressor still rotates but the centre nut doesnt rotate. I think this implies the anti-lock has sheared off?? I assume this failure cannot be fixed without removing the compressor (and draining the system down).

Thanks for the response.

MY2005 1.9Tdi PD Elegance.

Voltage is getting to the compressor and I have visually looked at the wiring from the baterry but not tested all of it. VCDS tells me it getting 1.7Nm load with the engine running but as you demand more cold it doesnt ramp up as it should, obviously the compressor still rotates but the centre nut doesnt rotate. I think this implies the anti-lock has sheared off?? I assume this failure cannot be fixed without removing the compressor (and draining the system down).

If the centre nut doesn't rotate, but the clutch plate does then the nut maybe loose.

With the engine off try rotating the nut clockwise with a spanner. It may not be easy to turn, but it should be smooth. You should feel it rotating the compressor. If it is solid, you will need a new compressor. Otherwise, tighten the nut whilst counterholding the clutch plate.

Cheers rwbaldwin for sharing your knowledge.

The centre nut wont rotate at all, so I assume the compressor is seized and 'anti-lock' rubber has sheared off the pulley and thats why it still rotates.

So, new compressor and new condenser and dryer unit....or new Octavia!

Dont suppose there's a cheap option :wonder:

...Dont suppose there's a cheap option :wonder:

Not really.

I would find a good indy a/c specialist to do the work.

If it is a seized bearing they may be able to replace the bearing or they may conclude that flushing isn't necessary because of the mode of failure. In that case, it would just be replacement of the compressor/drier and much less labour.

I would find a good indy a/c specialist to do the work.

Fingers crossed for next week, found an independant a/c specialist that seemed to talk sense with great prices (and 12months warranty on his work). I could be keeping my Octy after all

If this works i'll be getting the remapping done!!