Question on Auto Climate Control Reliability and Accuracy

[Fummins]

I think you should probably tear out all the blend door motors and rig up a bunch of choke cables to move the flappers instead. Far less complimicated.

[Jim Rogers]

I think you should probably tear out all the blend door motors and rig up a bunch of choke cables to move the flappers instead. Far less complimicated.

Believe it or not, I have been mildly looking into the possibility of doing just that!

Not from the get-go, but if I had an old Mirage with high miles and the HVAC system started giving trouble, I might just try to do what you suggest and rig up a completely manual system.

[foama]

Boy am I glad to have bought the simpler model!

[Jim Rogers]

Boy am I glad to have bought the simpler model!

As far as actuating the blend doors and heater core valve, is the simple model any different from the complicated one? Often times, that manual controls are only manual in the sense that they don't automatically control the temperature.

In those cases, when one adjusts those manual controls, the controls are really just switches that activate the same servo motors that the auto versions use.

I.e., there are often no differences between an auto and manual system once you get inside the dash.

Is that the case with the Mirage?

[Fummins]

As far as actuating the blend doors and heater core valve, is the simple model any different from the complicated one? Often times, that manual controls are only manual in the sense that they don't automatically control the temperature.

In those cases, when one adjusts those manual controls, the controls are really just switches that activate the same servo motors that the auto versions use.

I.e., there are often no differences between an auto and manual system once you get inside the dash.

Is that the case with the Mirage?

The manual temp controls is literally manual. It uses 3 push/pull cables. One for hot/cold, one to select where the air comes out, and the third controls the fresh air/recirc flapper behind the glove box. I don't know if the actual heater boxes are different. It might be that the auto temp models just have the motors bolted to the side instead of levers. I threw out the heater box I had laying around already but I believe it had provisions to mount a blend door motor in at least one spot? Would make sense to keep things simpler.

The only possible issue I could see going from auto to manual temp would be having one of the modules getting pissy. Probably wouldn't throw a cel but who know with these things sometimes.

[Jim Rogers]

The manual temp controls is literally manual. It uses 3 push/pull cables. One for hot/cold, one to select where the air comes out, and the third controls the fresh air/recirc flapper behind the glove box.

That's good to hear-- and it makes me want manual controls even more!

[foama]

As far as actuating the blend doors and heater core valve, is the simple model any different from the complicated one? Often times, that manual controls are only manual in the sense that they don't automatically control the temperature.

In those cases, when one adjusts those manual controls, the controls are really just switches that activate the same servo motors that the auto versions use.

I.e., there are often no differences between an auto and manual system once you get inside the dash.

Is that the case with the Mirage?

By the look of the photos, it seems the boxes could be the same, just other stuff bolted on.

[Christopher_B]

There is a way to use auto AND not use the AC compressor. I think you hold the snowflake button down for so many seconds. Found the info on this forum and one of the first things I did since we got our Mirage Feb. 1, 2021. In the colder months I do not want the AC running needlessly. If it fogs I will hit the defrost. I think that turns on AC automatically. So I can run auto temp without the AC light on.
The main and maybe only thing I like about the auto climate control is the fan ramping up when the coolant is hot or condenser is cold.
I figured this must not have a sun sensor because 74 in the daytime can be too hot on summer days and 74 can be too cold on same the evening.
I hadn't thought of 7Miles theory on the numbers not actually being degrees but only being a relative measurement that 75 is warmer than 70.
It would seem that there is a cabin temp sensor somewhere because the fan speed slows when the HVAC module senses the "desired temp" goal is close to or has been met.
The biggest gripe I have is the fan pretty much always runs on low speeds. NOW we have an intermittent and very slight blower motor chirp. I pulled the blower out after it made the noise a few days in a row. Held it in my hand in away from the duct work and turned it on to verify the source of the noise. Of course when I went to the dealer saturday it was not making the noise. The car has 55K and will be out of warranty soon.

[Wallythacker]

IIRC when you engage the temperature display on the dash that changes the profile used by the auto system. That would mean the sensor is ignored under normal circumstances. I can't recall where I read that.