My son has a Harbor Breeze fan that is about a year old, it will only run on one speed, low. When it was installed it worked great, now it does not work well at all . Any help would be great.

What controls the speed: pull chains, remote or wall switch?

Pull chain or wall switch.

If you have both a pullchain and a wall switch, is the wall switch for control of the light?

Another possibility is that the pull switch is set to low and is out of step with the wall controller.

The wall switch wii cut the light and the fan off,

Yes as it should. The wall switch must be truned ON and then try the pull chains. Do th chains do anything, turn ON or turn OFF while the wall switch is on?

Could the switch on the fan be bad, if so are they hard to replace and easy to buy at a Lowe's store, thanks