My wife's 2003 Boxster Air Conditioning compressor and interior fan plus automatic settings has stopped working. Previous day every thing was fine. But after overnight park??? I read some of the forum responses on this problem from years past and have checked all the fuses. Again "Ignition to On, prestart" you can hear the compressor and a fan engaging. "Upon engine start" everything goes dead including all the AC related controls (Auto, air flow, recirculate,etc). There are a couple of aspects to check I need clarification on:

1. Is there a refrigerant level or reading sensor that could cut everything off upon start?

2. The ignition switch has become increasingly harder to deal with...steering lock, etc. Does the switch have any cutoff function for the AC on startup?

Thanks, Perry (Old Guy, 50 years a Porsche Owner, 43 years a PCA member, still dreaming about simplicity of the 356 and early 911's).

 

I'm being drawn toward a refrigerant leak...the car would periodically emit a "Train Whistle Choo-Cho sound from the right air vent...actually quite entertaining!

Thanks, Perry

 

Perry,
You might try posting in the 986 forum section since that is your car's generation.
I don't know what the choo choo sound is all about, but the other symptoms sound like a failing ignition switch.
Ignition switches are a weak point in the 986/996 era cars, and when they wear out people report all sorts of strange symptoms.
Search the 986 and 996 forums for "ignition switch" and see if the search results sound familiar.