I recently bought a '99 996 and I'm working on all the little things that the last owner never took care of. One of these is the heater. I have no heat whatsoever. No matter how long the car has been running) Air blows and the AC seems to work fine but there is basically no temperature control. I assume that it's an easy fix but I don't know where to start. Is this common? I haven't seen anything in the forums. Any suggestions on where to start? Thanks

 

In line valve shuting off water flow to the heater core??? Just a guess. Never seen it done on P-cars but lots of others. Some cars hot water is always flowing through the heater core. So the heater core is always given off heat. You install the valve so during the hot months the cars is cooler on the inside.

 

I seem to be having a similar problem with my '99 996. I just had both condensers replaced and the AC is blowing super cold air. However it is actually so cold that I have water dripping in both footwells and I get extreme condensation around all vents along with window misting. I've played with the temperature, going from hi to low, but the temperature of the air blowing doesn't change. Even when set on high the air flow doesn't get any warmer. Does this mean I have no heater? The fan speeds adjusts but that doesn't really help. I don't know the technical details of the 996 AC system so is this likely to be a faulty AC control unit or could it just be something as simple as a disconnected wire or faulty connection?

 

if you are getting any wetness around footwell, the heater core is bad. it will cause fogging inside the car too so get it fixed. also, check all the fuses to make sure nothing is blown.

 

I removed the lower part of the center dash (shelf and cassette holder) and found a disconnected cable that looks suspiciously like one of the connections on the wiring harness of the AC. In fact it looks exactly like the connector that attaches to the resistor. Could a disconnected cable imply that the heating core is simply not connected and if so could that cause the symptoms I am seeing? The AC continues to work but when I go around corners the water flow into the footwells is pretty significant. Can see an easy way of attempting to re-attach the cable so will probably let the local Porsche guys take a look on Monday.

 

There is also the lose phone connector in that area.

 

Let me know what you find out about that connector. I had my radio out when I got the car and I guess I could have accidently disconnected something.

 

Let me know what you find out about that connector. I had my radio out when I got the car and I guess I could have accidently disconnected something.

 

also check the fluid in the radiator.

 

unlikely. if there isn't enough to keep the heating working, the engine would over heat. Also, 911 has few gallons of coolant.

 

Got an update from the Porsche service guys. The drains were clogged so they have cleared them. They also noticed that the A/C flaps were tie strapped to only blow cold! Unfortunately they had to pull the mechanic to work on another car so they will get back to mine tomorrow morning and see if the flaps can be repaired and also determine whether the heater core is even connected. Sounds like the previous owner just wanted the thing to blow the coldest air possible all the time. Hopefully it turns out to be a disconnected heater core and so no big deal.