erratic s40 Climate Control behavior

[rmcclellan]

The climate control in my 2000 s40 just starting acting erratically. The entire climate control system (heat, ac, rear-window defrost) becomes unresponsive (indicator lights do not come on and fans will not blow). Usually after 5 or 10 minutes it will start to function normally for 5 to 10 minutes, and then become unresponsive again. It seems to be an electrical problem, but I don't even know where to start. When this occurs all other dash board electronics (radio, dash lights, flashers, infocenter) function properly. This just started happening a few days ago. I've owned the car for five years and have never had problems with the climate control system until now.