My 2003 Chevy Silverado has dual climate control. We are getting ready to approach the air conditioning season. Last year I visited my mechanic to find out why the passenger side blows hot air when I have the A/C running. Apparently you need to remove the entire dash of the truck to replace a temperature sensor buried so deep that it will cost nearly $800 in labor to replace. An over-the-counter manual at the auto parts store even recommends seeing a professional mechanic to perform the work. I guess my passenger will feel a little heat during the summers. Dang Monkeys!
A lot of automatically controlled climate control systems on cars since about 1967 use "vacuum motors" to operate the dampers in the air boxes. These are usually just a bellows and light return spring that are controlled by the presence or absence of a vacuum.
I removed the airbox unit and replaced these actuators in my parent's 1972 Cadillac around 1990. It was a very successful result; however, I had to virtually dismantle and reassemble the entire Cadillac dash over 3 days to replace these "vacuum motor" components. I think they put this airbox sub-assembly on the line first and build the car around it.
I did a similar task in 1979 when I installed factory AC into the dash of my parents 1975 GMC Motor Home. I used a car AC compressor, dryer, muffler, expansion valve, condensors, and a new GMC airbox with vacuum motors, heater core, and evaporator installed. This also required a large amount of dismantling and reassembling. this also required finding a set of OEM accessory brackets that would permit mounting all the accessories including the compressor onto the 455 Olds engine without interference. The whole job took me 2 weeks of my summer break from college before I started my summer job. My dad then added the refrigeration oil and charged the 4.0# Freon 12 system. It worked very well, even visiting in the 107+ degree heat of Oklahoma, Kansas, and New Mexico.
These "vcuum motor" actuators are not unique to GM, because I had a similar issue with my 1987 Ford Taurus SW. I never got to dismantling the dash and replacing the defective components; so, this car had the heat and AC come out at the floor (no defroster action, and poor AC circulation through the car.). I knew how to pick my way through that repair, but never got the 2-3 days dedicated to that fix from when it broke in 1995 prior to selling it in 1998.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.