2001 540iM E39 A/C & heater climate control stopped working

[mtbokc]

Please Help! My 2001 540iM E39 A/C & heater climate control panel stopped working. I can hear the small fan inside working but none of the buttons light up or control anything. I have checked all fuses and the relays I can find but I don't know which relay(s) are for the A/C. Does anyone know which/where relay(s) are located and if there is a way to test the panel to make sure it needs to be replaced? Any suggestions would be greatly appreciated.