I suspect my AC is running low on gas....here's what happens...

Whether I press the small snowflake or the large snowflake buttons, all I get is the compressor cycling on for about 5 secs and then it switches off for 10 secs and then switches back on....and so on....

The condensor cooling fan comes on ok, and if I feel the pipes at the compressor, I can feel a cooling effect on one of the pipes.....

The large snowflake button does not seem to do what it is supposed to..i.e. when I press it, it seems the same as the small snowflake....blower fan speed is unaffected. I thought the blowers were automatically switched to speed 4 when the large snowflake is pressed?

The evaporator was changed by the previous owner in Jan 07.

Any ideas anyone?

cheers,

Taj.

 

Is it the compressor cycling or the fan in the bumper? Search for ballast resistor in the 993 forum.

 

compressor is cycling

 

Taj
if you have some time, read this thread.....
https://rennlist.com/forums/993-forum/351059-complete-a-c-diagnosis.html

 

+1
Also, it may be as simple as an overcharge. The 993 cab I bought a few months ago was overcharged and had the same symptoms. There is a high press cutoff that will disengage the clutch and cause short cycling. If you have a gauge set this is easy to diagnose and rectify.
The other possibility is the CCU buttons. They can get a bit dirty and not do their job. The CCU can be removed fairly easily and cleaned with a contact cleaner.

 

Absolutely fantastic thread from Brian! Thanks for the link..In my part of the world those two letters "A/C" are as important as "brakes"..