How Does A/C work on a Carb vehicle?

When vehicles were carbureted, what adjusted idle speed for the A/C compressor surge?

Was there a device on the carb that would slightly open the throttle?

Also, I am assuming that without a engine computer managing anything, the A/C system at that point would rely solely on pressure sensors to engage its clutch to compress?

I'm guessing from inside the vehicle, when turning on the A/C, you'd be (A) sending power to your low speed fan relay to turn on the engine cooling fans/ or engaging the clutch fan, (B) be turning on some sort of idle controlling solenoid on the carb and (C) sending power to the A/C clutch circuit (with a pressure sensor inline?)...
A little solenoid on the throttle linkage on my 84 Oldsmobile.
 
My ‘77 Oldsmobile was an icebox in any weather. 100 degrees, humid, idling in NYC traffic, it would still freeze you. The engine never overheated.

When cars like that (a luxury car, not a cheapie) were new, and when they were maintained, they worked great.

Most people’s experience with cars that had carburetors and AC are with 20+ year old heaps. Worn out fan clutches, poorly maintained cooling systems, undercharged AC, etc. That’s what I’m seeing here.

Not a fair assessment. That’s not how they were when new.
Exactly. People remember driving $300 rust buckets back when they were young and poor and state it like fact that that is the way they all were.
 
Exactly. People remember driving $300 rust buckets back when they were young and poor and state it like fact that that is the way they all were.
Thats good to know. I am thinking about different plans for a car. Car may very well be carb and def. want A/C for those hot days.
 
My ‘77 Oldsmobile was an icebox in any weather. 100 degrees, humid, idling in NYC traffic, it would still freeze you. The engine never overheated.

When cars like that (a luxury car, not a cheapie) were new, and when they were maintained, they worked great.

Most people’s experience with cars that had carburetors and AC are with 20+ year old heaps. Worn out fan clutches, poorly maintained cooling systems, undercharged AC, etc. That’s what I’m seeing here.

Not a fair assessment. That’s not how they were when new.
I recall a rental, full size car without many miles on the odometer we were driving out of NYC one time. 90 something, stop and go traffic. Had to kill the A/C when the temp idiot light came on.
 
Idle was too low or a bad fan clutch. Those fail more than most people realize
I've had a bad fan clutch on almost every old car I've owned over the years. Sometimes they don't engage enough others completely engage and sound like a jet engine taking off. I much prefer electric fans now even on an old car.
 
I've had a bad fan clutch on almost every old car I've owned over the years. Sometimes they don't engage enough others completely engage and sound like a jet engine taking off. I much prefer electric fans now even on an old car.
Going back to my original post about the very common failures of A/C systems on cars back in the day: they were not made well at all. Be it compressor, fan clutch, idle speed, gremlins or whatever, they very often failed when it got very hot.
 
Going back to my original post about the very common failures of A/C systems on cars back in the day: they were not made well at all. Be it compressor, fan clutch, idle speed, gremlins or whatever, they very often failed when it got very hot.
In my experience clutch fans failed at higher mileage. I had one compressor fail at high mileage. My condenser and current compressor are original 1987 parts.
I think you mean to say they failed at higher mileage. They don't just stop working when it's not.
I remember riding in my dad's friends 1979 Caprice station wagon as a kid. It was a hot hot day and that AC was blowing ice cold and my sister and I kept playing with the power windows as we hadn't been in a car with them before. This was around 1993 when that car was 14 years old. Years later when I got my license I'd drive and 87 Cutlass supreme and later got an 87 Caprice for a winter beater both had working AC.
 
Going back to my original post about the very common failures of A/C systems on cars back in the day: they were not made well at all. Be it compressor, fan clutch, idle speed, gremlins or whatever, they very often failed when it got very hot.
Oh and your one broken rental car doesn't represent all the other cars that had working AC back then.
 
Oh and your one broken rental car doesn't represent all the other cars that had working AC back then.
I didn't ride in many cars with A/C back in the day, but the majority did not work well. We are all glad that you never had any problems with those antique systems back then.
 
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