Hey folks, new user here, started with a 944 S2 back in '95, and then a 993 sometime in the late 90s. She's been running fine, and I've gotten more adept at R&R thanks to lurking around here.
So I decided it's time to see why my a/c quit last summer. The compressor engages, but the vents just blow air at ambient temp. Looked to see if the condensor far was running and it's not!! Narrowed that down to the infamous ballast resistor and jumpered pins on the relay to get the high speed fan blowing. Still no change. Bummer, that would have been nice.
So I got a set of gauges and got to work. Here's the readings and steps I took with ambient temp of 71 F:
Engine Off: Low=32, High=32
Engine Idling: 4, 95
Engine @2k rpm: -4, 105 (low side was reading a vacuum)
At this point I figured I'd put a wee bit R134 in to get the high side to spec. After this:
Engine Idling: 16, 160 (low and high side in spec now)
Engine @2K rpm: 2, 180
Engine Off: 70, 70
Feeling the lines, the high side is hot from the compressor to the condensor. From there, it all feels about the same - cool but not cold. No change in temp feel before/after the expansion valve.
What do ya guys think? I'm leaning towards (or is it hoping) Expansion valve clogged. But, I just don't know.
Would greatly appreciate any tips on isolating the problem.