linderpat

So my A/C just up and died - one minute, blowing cold as it always does. Do an oil change, brake fluid bleed, and go for a ride, not blowing cold anymore. Seems rather sudden. Is this how they fail? What are the possibilities? Compressor seals, leaking line, what else? How easy/hard is DIY?

michaelo

Check / Change the fuse and report back.

linderpat

Would a fuse affect how cold the air blowing out of the vents is? I will check, but everything seems to be working fine, except no cold air.

JABowders

If you think you want to take a stab at it yourself... When turned on does the compressor's electrical clutch engage and cause the compressor to run (this is part of the fuse bit). Yes the inside fan will run and blow air even if the compressor is not engaged.
For about $50 you can get a AC Pro recharge kit (the one with the gauge) at your local auto parts store. This you can use to quickly double check your system for pressure and if low you can use the kit to filler' up (it has some sealant to stop leaks but only small ones) so after the top up your system should work again and if after a day or two and the AC stops blowing cold, well then it is obvious it is a much bigger issue.
It is possible you have damaged a condenser (one in front of each small cooling radiators), a line, or even the evaporator.

BUT if the system has been working trouble free and suddenly just stopped... I got money on the compressor's electrical clutch not engaging either because of a fuse, or the Tech disconnected the wire feed to the clutch and it is not completing the circuit.

Best of luck.

linderpat

Thanks guys. since I'm the tech, I know the wire feed to the clutch was not (purposefully) disconnected. I will do the condenser check and the fuse check - hopefully that's it - usually the simple things are all it takes. Not likely there is damage to the front condensers, since I have screens protecting them mounted inside the vents (and they help keep the crud down - just cleaned them out well a month or so ago). I'll check and report back.

Presto

linderpat

fuse is good (I think - I could not find a fuse chart for my year/model, so I looked at just about every fuse). The compressor and clutch appear to engage properly. I could not tell if the condenser fans came on though.

swingwing

linderpat

OK, I did the fan test, with the car up on lift bars and the wheels off. Fans definitely not running. I looked at the fuse chart (thanks Petza - tucked into the fuse box door), and checked all applicable fuses which were ok. I know there are relays for the fans, but I'm not sure which is which. Does anyone know where to find the relay chart? There aren't that many relays - I think it's the relays tucked up above where the fuse panel is.
As to the fans, would that be enough all by itself to keep the a/c from blowing cold?

NuttyProfessor

If your fans aren't running when you turn on the car with the AC on, then more than likely, you have worn out fan resistors. If I'm not mistaken, the process for replacement is the same as the 996. Go to YouTube and search - Porsche 996 or 997 resistor. Lots of great DIY videos on this subject.

linderpat

Thanks - could it also be bad relays? Seems more than coincidence that both would fail at the same time? Also, do the fans alone cause the a/c to blow warm if they stop working?

NuttyProfessor

Yes, but there is also a chance that you have a leak too. But the fans work in conjunction with the AC system to provide cold air when the car is not in motion. Cross one bridge at a time. First, turn the car on with the AC at full blast. Examine the front fans. If they're definitely not on, then more than likely its the resistor. Usually the relays hold up much longer, and so my vote is on the resistor. They wear out much quicker. Check out this video...

swingwing

I disagree. Before I bite on replacing resistors I'd check for 12V at the fan connectors. You'll need to pull the front wheels and the wheelwell liners to get access to the connectors. Here's a good video on fan issues:

swingwing

There's something about your sudden loss of AC that's perplexing. You haven't mentioned checking the refrigerant; if it's gone there's nothing for the compressor to work on so that may cause the fans not to run. You can buy a can of refrigerant with built-in pressure gauge at a parts store. Alternatively any decent repair shop can tell you quickly if the refrigerant is low or gone. If it's gone the kicker is finding out where the leak is.

docdrs