At the risk of sounding silly, if all the function it is supposed to do work, then the switch is clearly working.
If something is not working, then you just need to follow some basic troubleshooting to see if there is electrical power going to the device that is not working.
To do this you need a wiring diagram and a multimeter. You use the multimeter to trace the power from the switch. if no power at switch, then the switch is faulty, otherwise it is a wiring fault or a device fault.
Unless you know what you are doing, this can get a bit tricky, so you are probably best to take your vehicle to an auto electrician and tell him what is wrong.
Answers & Comments
At the risk of sounding silly, if all the function it is supposed to do work, then the switch is clearly working.
If something is not working, then you just need to follow some basic troubleshooting to see if there is electrical power going to the device that is not working.
To do this you need a wiring diagram and a multimeter. You use the multimeter to trace the power from the switch. if no power at switch, then the switch is faulty, otherwise it is a wiring fault or a device fault.
Unless you know what you are doing, this can get a bit tricky, so you are probably best to take your vehicle to an auto electrician and tell him what is wrong.