Problem with electric switch....explained, help needed

The switch (buttons) that are located on the end of the wiper switch arm, that are used to switch the display on the dash between your current and average MPG, number of miles diesel left in the tank, time, outside temperature etc, has stopped working, now I am just stuck looking at the outside temperature on the dash board display it operates.

Have no idea where to start looking for the problem, wire maybe or a fuse (am wishing for), are where to check the wires for likely problems.

Wipes and every other function via the switch arms still work fine, its just this simple one function of been able to change the display that has stopped working, unsure if the reset button underneath the leaver used to reset the display is working ether, due to been stuck on the temperature display this button give no sigh of weather its working or not.

and hoping to find other possible easier solutions to stripping out the dash to check the wires behind the switch its self to try first, to eliminate before the need to do that, I list of places and things to check for, in order of quick and easy to do format, would be perfect in order to hopefully find and resolve the issue in an easy to locate place.