As the other post says, you switch is bad. Some people have said they have taken it out and cleaned it. Often the contacts are burnt and not worth fixing. If you look arounf on the Internet, you can find it cheaper. I think I paid about $100 fron FCP Groton. 1-877-634-0063.

Easy to remove old one, but in a different way than one might think. Only the inner grey switch panel needs to come out, not the outer colored plastic piece that the switch assembly is pressed into. Many remove it by slipping something in between the grey and colored parts and prying up. This will work, but you risk damaging the colored plastic piece. The Volvo dealer showed me the best way. Use a metal tool of some sort that has a "hook" at one end. At about the center of the switch assembly, catch the hook under/inside the switch assembly and pull up (do not hook it under the switch buttons themselves). It will pull straight up and out with some moderate to harder pulling.

Good luck