There is a temp switch on the very bottom of the servo. Connect the 2 lines (black and yellow I believe) together to bypass it for troubleshooting.
If you really want to risk the wrath O' the SERVO GODS then isolate your ACC vacuum circuit from the rest of the cars vacuum systems. It does need to be connected to the vacuum reservoir and you need the one way valve installed.
Before starting follow these steps:
1-Sleep with the "Operation of Automatic Climate Control System" manual under your pillow. (A yellow binder helps but some swear by a green and black one)
2- Get up and burn some incense with a "woody" character. (Reminiscent of the Black Forest).
3- Put this on repeat in the garage:
http://www.youtube.com/watch?v=gChOifUJZMc
4- DO NOT let your Mity Vac get more than 2 feet from your RIGHT HAND during the procedure. And just go ahead and shave your head before starting. This will save time.
Allow 6-8 weeks for thorough diagnostics. (Add another 2-4 weeks for remedies)
Light hallucinogenics have been proven to be helpful but a little weed smoked through a windshield washer and vacuum line bong helps...