I had a similiar issue but it was in a Dodge Dakota so not sure if this will help or not. At first it was just a Blower motor resistor which cost 7 bucks from the dealer. About 4 month's later it went again. Turned out it was an issue with the blower motor that was causing the resistor to burn up. Once i replaced the blower motor all was fine.
thanks... mm i meant the blower motor speed setting .. #4.. u know how it has 4 speeds.. well anyways. i removed my resistor.. yeah its was all Fu'd up .. lol... replaced it .. like 18 bucks.. a/c works fine now..