gtroth

AC was working nicely on Friday. Today (the following Monday) it won't stay on. With the big snow flake button pushed, fan comes on at high speed for a few seconds and then shuts off for a few seconds, and repeats this cycling forever. It's never on long enough to for me to tell of the air is cold or not.

An ideas where to start?
Many thanks!

TMc993

http://www.bergvillfx.com/porschehvac1

gtroth

Yes, thanks. I read that site first as usual for AC issues. It doesn't seem to cover my symptoms.

pp000830

If it cycles on and off in a regular sequence it seems to me the CCU may not like the fan motor because it is drawing too much current or some other component is cycling it. Have you run the OBD Codes as the system is one of the modules that reports faults.

P-daddy

Have you checked your AC series resistor? It's located on top of the AC condenser left front wheel well.

SpeedyC2

My AC acts in a similar fashion. When pressing the high speed fan - or defrost - the high speed fan will turn on and off at irregular intervals. High speed will work most of the time, but occasionally cut off for a few seconds.

Most other functions - low fan speeds, mixing vents, etc. - seem to work properly and the AC series resistor was recently replaced. I think I'm going to start searching for a vacuum leak...

techman1

The large snowflake is a shortcut for max ac.

Try the setting for Max AC yourself. Use the small snowflake, Fan on high, main vents only, recirc on.
Does it seem to work properly?

tom97c4s

I had that problem once and took the cover off of the dash AC controls and blew in some compress air and it has worked fine since. It may just need a cleaning.

davesnothere

Before tearing into the whole system, try the compressed air / electronics cleaner on the big snowflake switch. I had what sounds like this exact problem recently and all the other modes except big snowflake worked fine; it was simply a switch contact issue.

NYC993

That only affects the external fan that blows over the condenser.

P-daddy

I stand corrected. I read it too quickly. Thanks NYC

ToreB

gtroth, check the rear fan operation. A failing rear fan blower/fuse/resistor will make the Climate Control Unit shut off the front fans.
See further details on testing here: http://www.bergvillfx.com/porschehvac1

Cheers,
Tore

KeninBlaine

Totally agree. Mine is erratic if I press the large snowflake (shortcut) button, but runs fine if I use the small snowflake and manually set the fan etc.

Cactus

This is your problem. Had the same issue.

gtroth

Ok, so seems like it is the big snowflake button misbehaving. Little snowflake with fan on high runs cold and steady. Fan speed on high seems like it is one speed slower than with big snow flake, but totally comfortable for now until I can fix the switch.

Many thanks!