Vacuum motors are so last-century

The Car Talk column in my local paper said the blend doors in the climate control system were powered by vacuum motors. Haven’t manufacturers adopted electric motors yet? For hybrids or electric vehicles???

Most are electric now. Calm down.

What car? Was the column responding to a questsion about an old car? Was it an old column?

Cars used to have quite a few devices operated by vacuum. My Aunt had a 1940 Ford convertible and the top was raised and lowered by vacuum motors. My 1954 Buick had a windshield washer pump that was powered by engine vacuum. Many cars had vacuum operated windshield wipers. You could buy a,wolf whistle horn that operated from engine vacuum. The vacuum operated HVAC controls came along late in the game–originally these controls were mechanical cables. Vacuum powered accessories are great–they don’t blow fuses. Like the South, the vacuum motors will rise again!


S10s and Astros used vacuum to move the mode doors. I believe the Astro’s last year was 2005.

But to be fair, the successors of both of these vehicles didn’t use vacuum to move the mode doors

So yes, cars designed in the 21st century are generally not using vacuum for hvac functions

With all due respect, why are you getting worked up . . . ?!

I’ll bet you lunch that column was in response to a reader’s question about an older car. And if you listen to the car talk reruns on the radio, they clearly are rebroadcasting old calls from the early 1990s.

If that newspaper column featured both Tom and Ray, then it was clearly several years old, and was a reprint

Problems with the old vacuum operated systems were most often under the hood and easily diagnosed and easily/cheaply repaired. The digitally controlled electic systems are more prone to costly failures beyond the abilities of most DIYers. But then the old cable operated systems were quite adequate. And there were those heaters that were turned on and off seasonally under the hood.

Weather my vehicle has vacuum or electric to operate the blend doors is not on my list of things to worry about.


My old diesel actually had a vacuum motor to generate needed vacuum for the transmission, etc. It was mounted right where the distributor would go on a gas 350. Of course when it went south, it was a couple hundred to replace it.

And even now the applications are mix and match.
My screen is set on Expeditions right now and My 08 has three electric actuators but toggling through the pics I see 06 having two vacuum AND one electric together.
– 2010 f150 all electric…2010 Ranger Two vacuum, one elect…
…'14 E150 van…three vacuum, one electric

Floutadad, did we answer your question???

Does anyone recall all the cable operated functions on old Fords. I recall driving several Falcons and Falcon Rancheros in the early 60s that had push-pull controls for choke, throttle, heat on-off and floor/defrost. Did twisting the heat on-off knob operate the heater fan? And wasn’t the ignition switch on the left side of the wheel? And while the original Mustang had the Falcon instrument cluster I don’t recall it having a manual choke or all the push pull controls on the heater.

I do not care what system as long as it works,

We had a couple Falcons, 60 and 62 I think. I recall the choke knob and the left hand ignition but not the heater controls.

From the posts we see here on this topic, the order of reliability for methods used to effect vent door movement, from most reliable to least reliable:

  • cable actuation
  • vacuum motor
  • electric motors

Both my vehicles use cables, and never had a problem with either over a combined 60+ car-years. Very few complaints here about failures of cable actuated vent doors, lots for electric motor actuated, especially the servo-motor type. And since fixing them can require removing all or portions of the dash, it can be very expensive. I expect there’s been lots of mechanic’s boat payments funded from this source.

There’s no fundamental problem with electric motors of course. Force is force, electric vs mechanical. I think the problem is that to place an electric motor where it needs to go, it has to be small, and small electric motors just don’t have the force that a vacuum motor or a cable actuated mechanism does. Another problem, an electric motor usually has to be geared for that application, and the plastic gears that are used tend to strip.

@Triedaq Ah yes, vacuum windshield wipers, I remember them well. When climbing a grade in a rainstorm, you had to lift your foot off the gas every once in a while so the wipers would do another wipe.
I have a feeling those have about as much chance of making a comeback as 6 volt batteries do.

@B.L.E. Now that the U…S.has established diplomatic relations with Cuba, trade will follow. We will have an influx of cars from the 1950s and 1960s, some with 6 volt systems and many with vacuum wipers.

4wd switches on AMC vehicles in the 70-80’s were vacuum.

Also hidden headlamps were vacuum. If you saw a vehicle with head lamps half open there was a vacuum problem.


“Now that the U…S.has established diplomatic relations with Cuba, trade will follow. We will have an influx of cars from the 1950s and 1960s”

Not entirely correct, from what I understand

I believe 1959 was the last model year of US vehicles sold in Cuba, at least through regular channels

So there won’t be any 1960s muscle cars coming from the island

Let’s also not forget that many of these cars that survived have been heavily modified and/or butchered, in order to keep them alive. Many of them have totally incorrect engines, transmissions, or both, among various other changes/modifications

They won’t hold a candle, versus your typical restored car featured in Hemmings, as far as quality and originality goes. But they might have a more colorful history :smiley:

I suspect measures will be taken by the Cuban government, to ensure that these cars you mentioned do NOT leave the island. Unless somebody knows for a fact that I’m wrong . . . ?

Let me clarify . . . I don’t think these cars will be allowed to leave the island, through regular channels

There’s nothing wrong with vacuum motors. They’re reliable and far cheaper than other means excluding cables.

If climate control vacuum motors are so last century then what about other vacuum controlled items such as purge control solenoids, EGR vacuum regulator solenoids, electric air management solenoids, PCV valves, and intake manifold runner solenoids just to name a few…