Apologies in advance if this is a stupid question. I just bought a 2005 Elise with low miles. Everything seemed good with the HVAC and the car passed a full PPI. Now, I can turn the blower on any of the 3 speeds when the engine is off but the key in and on, but with the engine running it doesn't seem to respond to any AC controls. Am I doing something wrong, or is something broken?