Heater fan Problem

[OrangeD]

The heater fan is behaving intermittently, it stops of its own accord, and pulses on and off when in manual mode. It will only go to two bars below max fan speed, and the fan only seems to start blowing when it gets about halfway up the scale.
any help will be great.
Thanks

[anonymous-user]

Give us a clue - such as what car you drive.

[OrangeD]

Sorry Boxster S 986

[thegoose]

Similar symptoms were common on BMW E39's and it was caused by a faulty temp sensor thingummybob, usually referred to as a hedgehog due to its appearance (lots of aluminium flat-topped spikes, kind of a heat-sink. The climate control responds to a signal from this so it fails the climate control gets very confused. Worth checking if your car has something similar.

[OrangeD]

Thanks for the Response, I actually tried swapping that today, believe its fan driver or resistor, I've checked the the fan itself and it is working, also the ignition switch, tried swaping the relay, all to to no avail. I'm currently wondering whether to gamble £100 on a second hand control unit