Heat, A/C not working right
 

My car's heat isn't responding to the temperature setting on the climate controls. The fan works fine, but the heat is stuck on high. No matter what temperature I set it on, the heat blows super hot from the vents. Anyone have experience with this problem?

Did you have any recent work done? I have not experienced this issue with my boxster, but I did with the audi A4. The guys who changed the oil had to disconnect the air, and just did not reconnect it. Took two seconds to fix, but I was worried. That is the best insight I have for you. I hope it helps. :cheers:

it's either one of the actuators or one-of-three temp sensors in the system that allow outside air to mix and/or restrict the airflow over the heater core.

Make sure all electrical connections are tight and corrosion free. Next, with an assistant, get under the dash and make sure that you watch the various bowden cables moving the flaps when the assistant changes the temp and vent settings, especially the one to the temperature valve.

:cheers:

This may sound weird but another potential cause is the ignition switch. When mine went bad heater blower, temp, and many other strange symtoms occurred. Easy fix...search this forum.

Actually, I just replaced the ignition switch. I've had a couple of other electrical gremlins lately, such as the cruise control and top switch being temperamental, so I tried the ignition first. I've got a funny feeling I may need to replace my alternator regulator...another problem lately is that the dash lights fluctuate at idle.
Any other thoughts?

Well the alternator could be an issue. There is no regulator as such. This is done by integral diodes. Though these can be replaced separately, if thealternator has been in service any length of time, it's much better to rebuild it, getting a new bearing and windings in the process for almost no extra $.

How old is your battery? A weak or dying attery can take the alternator along for the ride.

:cheers:

The very first sign was the battery, which died sometime last year. I replaced it with a Braille lightweight unit. I didn't go with the lightest model; mine is the 11.5 pounder.