2000 S40T Odd Noise Topic is solved

[Ken]

I noticed an odd noise when my partner picked me up this afternoon. Its a kind of continuous pitch similar to a ringing in the ears. Its not very loud but is annoying all the same. It can be heard from outside the car as well as inside. It only occurs whilst the engine is running.
This sound changes pitch momentarily when the battery is put under load, such as switching on the lights or rear window heater.
This suggests its something electrical?
I cant quite pinpoint the source of the sound but then I havnt had a good look yet (its dark and cold outside)
Nothing else seems to be affected (yet) by this, and as I say the sound is not particularly loud but it wasn't there the last time i drove the car.
Im baffled..any ideas??
On an entirely different subject im thinking of getting a 6CD changer as a volvo extra. Where would this normaly go? I thought it would go in the boot but the dealer suggests it gets mounted under the passenger glove compartment...what do you think?

[vjck_uk]

Hi there.
The noise could be the auxillary belt as when you load the altenator like switching on electrical items it will make more noise if it's slack or worn.
The tensioner may need looking at or the belt replacing.
Vaughan

[Ken]

Thanks for your suggestion Vaughen.
I just got the car up on the ramp at the tyre fitters and found the noise to be coming from inside the fuel tank. Therefore suggesting the fuel pump.
I just wonder if it should be making a noise at all?
See my other post "Noisy fuel pump in S40"
Thanks again for commenting.