Cabin temperature sensor

[cheetahmoon]

Help appreciated. The cabin heater only blows cold, or hot when set to high. It seems likely that the cabin temperature sensor has gone. This is located behind the passenger heater vent on the dash. The unit, part number 99665324100 is a fan and some wire which I assume is the sensor. The fan works ok. A new part is very expensive, £300! Does anyone know if these can be fixed or substituted with an alternative part number? It seems to be a common problem, and expensive to fix so ideas welcome….

[Starter986]

What year is your Boxster. That will narrow things down.

[cheetahmoon]

Originally Posted by Starter986

What year is your Boxster. That will narrow things down.

Thanks! It’s a 2003!

[JFP in PA]

Originally Posted by cheetahmoon

Help appreciated. The cabin heater only blows cold, or hot when set to high. It seems likely that the cabin temperature sensor has gone. This is located behind the passenger heater vent on the dash. The unit, part number 99665324100 is a fan and some wire which I assume is the sensor. The fan works ok. A new part is very expensive, £300! Does anyone know if these can be fixed or substituted with an alternative part number? It seems to be a common problem, and expensive to fix so ideas welcome….

The sensor may be near the blower fan, but it is not part of it. Depending upon you VIN, it is either 996-573-925-00 or 1H0-907-543-A. Cost is between $50 and $100 US.

[cheetahmoon]

Thanks JFP but its not the refidge sensor its the cabin temperature sensor. It's located behind a small vent on the passenger side of the dashboard (part number as original post). The unit has a micro fan which forces air over a wire temperature sensor.

[pilot4fn]

Originally Posted by cheetahmoon

Help appreciated. The cabin heater only blows cold, or hot when set to high. It seems likely that the cabin temperature sensor has gone. This is located behind the passenger heater vent on the dash. The unit, part number 99665324100 is a fan and some wire which I assume is the sensor. The fan works ok. A new part is very expensive, £300! Does anyone know if these can be fixed or substituted with an alternative part number? It seems to be a common problem, and expensive to fix so ideas welcome….

Due to very expensive price for OEM replacement, I went with used from a reputable braker (Douglas Valley, UK) and the temperature controls works like a charm now.

[cheetahmoon]

Thanks Pilot- I agree; incredibly expensive and a S/H unit is likely. But I think its a thermistor that has failed (cost around £5) and its definitely not the micro fan - so it might be a great service to the Boxster clan if we could identify a repair solution.

[cheetahmoon]

Here's one solution, a cheaper bodge from our 911 friends.

911uk.com - Porsche Forum : View topic - Internal cabin temperature sensor failure / replacement

Older Porsche owners have tracked down their Thermistor Specs for 924s etc. They found the Thermistor specs in data sheets a residence at say 25 degrees and then the rate that resistance varies with temperature.

If anyone has access to this information for the 986 then thermistors are about 75p a lot cheaper that £300 for the replacement part or even £80 for a second hand one!

Does anyone know where we can get the data?