Hi, (1999 S80 T6)

I've tried to search for the following problem in this forum without luck. Maybe I'm the only one with this problem. When applying a slight pressure to the brakes I get a squiky/chirping noise from the area underneath the dashboard near the climate fan. If I brake heavily, the sound is not there. The sound only happens when the fan is on. The sound does not increase or decrease with fan speed. I have checked and greased the glove compartment light swith and ruled out the compartment strut. I have taken out the fan and the fan runs perfect without any noise. There is still the squiky noise when the fan is out of the car while braking.

I'm wondering if there is something that opens when the fan swith is turned on that could be vibrating while breaking (or occasionally when standing still ). I can hear a faint sound of maybe a relay or motor when I turn on the fan swith. This sound occurs as well when the fan is removed from the car.

Thanks,

Par

i MAY be mistaken as I'm very new to S80;s but doesnt the brake pedal have a pump to keep it air pressurised? If you notice, you hear some air being exhausted from the pedal when you press it and I always assumed that that whirring noise was the pump putting the air back in (thus making the braking action less harsh and more gradual)...
just a theory, let me know