Porsche Repair: condensate blowing out of AC Vents, heater hoses, engine cars

Question
My 1985.5 AC was just charged and is now spraying condensate through the vents.  Soaking the rugs shorting the radio etc.  I am being told to just clean out the drain for the venting system. Can you tell me where this might be! Accessed from inside the car, under the hood, etc.  Any info. you can offer would be fabulous.
Looking forward to hearing your thoughts, and where I can clear this damn drain!.

Many thanks,
Chuck Waldes
PH:  201 666 3587
Cell:  201 788 5846
FX:  201 666 1279

Answer
Hi Chuck

I'm going to assume you're talking about a 944, since that 85.5  designation is a common way of identyfying those cars.  Anyway, this answer will actually cover all front engine cars with air conditioning.

First, I'm a bit surprised you have that much water entering the passenger cabin.  This means you are in a very high humidity state, right?

Unfortunately, I don't have access to a 944 anymore, which would mean I could go root around and get really greasy getting you the exact answer.  My daughter sold her little 944S2 rocket, so the good news is I don't have to maintain it, but the bad news is I can't take it on long test drives!

Here's how to find the drain.  Locate the two A/C refrigerant lines (looking much like highly reinforced heater hoses) that start at the A/C compressor (on the underside and driver's side  of your engine compartment).  When these two lines enter the firewall leading to the passenger compartment they terminate at the A/C evaporator, which is creating the excessive moisture.  Normally, the evaporator is located just between the firewall and the dashboard somewhere above the passenger's footwell.  Excess water collects in the evaporator's built-in drain pan and is supposed to drain back through the firewall, eventually leaving a harmless little puddle underneath the car, whenever the car is parked.

In your case, the drain pan probably overflowed, so that would be another indicator of the exact location of the evaporator.  The wettest parts of your flooring are likely nearest the offending drain pan.  This pan has it's own drain hose that snakes back through the firewall.

So what I'd be looking for is a hose exiting the firewall, very near the bottom of where you imagine the evaporator would be.  The hose will be pointing downward and it will likely look like it was flattened a bit by an iron, especially at its tip.  Most of these drain hoses have this pinched end, which is supposed to prevent bad things like dirt and dust from entering.   It's also suppossed to let other bad things, like tiny leaves coming into the sytem with the incoming airflow, and  excessive water, drain out.  This pinched end is the only point where the water could get trapped.  If you are lucky, the pinched end will be visible and accessible from below; and the eraser end of a pencil will easily open and clear any obstruction.

Dave

P.S.  I certainly wouldn't spend any more money letting that A/C technician search around for a more significant problem, but if you don't live in a high humidity state, I'd suggest one other thing.  While thinking about this response, I searched for, but couldn't find, some documentation I was looking for.  I seem to recall that excessive condensation blowing on a car owner is a symptom of another A/C problem, besides a block vent.  I'm not trying to stir things up, but you might want to get a second opinion after your vent is clear and more condensate appears where it's not supposed to, if it does.  If not, problem solved!