It's your ac door actuator

 

Could be the fuel pump.

 

Hazard switch is least likely. If you're sure it not from under the hood (and so not the HP fuel pump) then my vote goes with spdygxp's A/C flap actuator.

 

Let me ask a stupid question.....Do you have Windrestrictor door sills? Let me explain why I asked. I have them and last summer when I was in the middle of replacing one, I didn't realize that I didn't tape the leads to the LED up enough. It started out as a click in the dash and within several days was a low loud electrical hum when I would hit bumps....it took me 2 weeks to find it! (its not that windrestrictor didn't send me a replacement, I was trying to figure out how to keep it from coming up off of my bent OE doorsills.

 

Don't know what the gentleman's problem is but it isn't the HP fuel pump. If you read the first post in the thread he clearly states that he has a base Solstice.
Just guessing but I too would go with the ac flap actuator.

Here is a place to start.
http://www.solsticeforum.com/forum/f12/help-heater-blend-door-actuator-issues-71681/

Sounds like this?

 

Thank you guys so much. It was indeed the blend door actuator, picked up the part for 30 dollars, was a pain to get to but the clicking sounds are gone and the a/c controls work perfectly now.