Instrument panel lighting
The instrument panel lighting illuminates when
the ignition key is in position II and the light
switch (1) is in either position 
Move the thumb wheel (4) up to increase brightness or down to decrease brightness.
See also:
Oil volume
...
High beam, Halogen
1. Remove the headlight housing from the vehicle (see page 306).
2. Remove the cover over the bulbs (see page 308).
3. Remove the bulb by turning it counterclockwise and pulling it straight out.
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Warranty
As you'd expect, the Volvo S40 saloon is supported by a comprehensive
warranty. The standard mechanical warranty is three years/60,000 miles
(whichever comes first), plus there's a three-year, unl ...