Sorry to post this in the general section but I want as many eyes as possible on this one.
My heater doesn't work most of the time on settings 2 and 3 and so yes it sounds like a resistor pack failure. So today I bought one and thanks to the brilliant info on this site, I had it fitted in about 10 minutes. At the time I also checked for water ingress and pollen filter blockages. All fine. The motor seems to spin freely too.
I turned the blower on and for about 10 seconds it worked on '1'. Then it died again.
Basically more often than not it will not work on anything apart from '4'. Sometimes when I get in the car it will work for about 5 seconds on say '3'... then stop running and only work on '4' again. Very rarely it'll work for an entire journey. When I turn the dial to '1' I get do hear a faint click coming from near the relays on the left hand side behind the grove compartment, then and another louder click when the dial reaches '4', at which point the motor always spins up fine. I then get another faint click when I turn it off again.
So it isn't a resistor pack problem and it doesn't sound like the control knob as it is making something click everytime I go from off to 1 and 3 to 4. The temperature is fine too - just the blower speeds.
Not knowing much about electronics has left me a bit foxed with this one. Oh and I'm not covered by any warranties before anyone asks. Any ideas?
Thanks for any help in advance.