Focus Air conditioning

[Wang.S]

I have a 17 Focus.
It sits for weeks at a time, but always starts and runs great. Great car overall We wont talk about the transmission. Sensitive word around here.
This last time I started it after sittng for almost 3 weeks, the battery seemed to be down on its luck, but it started quickly.

Over the next couple days in the heat it was doing some weird AC stuff.
Things such as changing the auto set temp on me to another temp. Not being on auto, starting at the LO setting, fan speed changes, but on Auto that could be normal.
Anyways, on the hottest day of the week, it was blowing hot air. It felt like a trip back in time sitting in the back seat of my Dads GT500 with no air, power windows or anything fancy, heading to A&W for dinner, and you could literally feel the sweat pooling in your ass crack.

FML, blend door problems? could it not be just a Ranger thing?

I know our Rangers are so sensitive to voltage, and shut things down if the battery gets week. So I charged it.
As of right now, the AC is working normally, and over the next couple days I should be able to determine if it indeed solved.

So, just a heads up I guess, I see some Ranger folk talking about problems similar, I thought it could be applicable to some people, and maybe you don't need to get your blend door fixed after all.

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[Fawnbuster]

I have a 17 Focus.
It sits for weeks at a time, but always starts and runs great. Great car overall We wont talk about the transmission. Sensitive word around here.
This last time I started it after sittng for almost 3 weeks, the battery seemed to be down on its luck, but it started quickly.

Over the next couple days in the heat it was doing some weird AC stuff.
Things such as changing the auto set temp on me to another temp. Not being on auto, starting at the LO setting, fan speed changes, but on Auto that could be normal.
Anyways, on the hottest day of the week, it was blowing hot air. It felt like a trip back in time sitting in the back seat of my Dads GT500 with no air, power windows or anything fancy, heading to A&W for dinner, and you could literally feel the sweat pooling in your ass crack.

FML, blend door problems? could it not be just a Ranger thing?

I know our Rangers are so sensitive to voltage, and shut things down if the battery gets week. So I charged it.
As of right now, the AC is working normally, and over the next couple days I should be able to determine if it indeed solved.

So, just a heads up I guess, I see some Ranger folk talking about problems similar, I thought it could be applicable to some people, and maybe you don't need to get your blend door fixed after all.

I'd like to hear more about the A&W! ?

That brought back memories. Very few if any around here left although there are still a few family owned drive in diners around, The Suds and Mug n Bun, both have great rootbeer, one you can even buy it by the gallon jug.

 

[Wang.S]

I'd like to hear more about the A&W! ?

That brought back memories. Very few if any around here left although there are still a few family owned drive in diners around, The Suds and Mug n Bun, both have great rootbeer, one you can even buy it by the gallon jug.

the retro aspect of the A&W is what I wish was around today.
it was the one where you pull up, turn your lights on, order, and they bring it out to you on a tray to hang on your window. Loved that experience as a kid

 

[RedDakooter05]

Well times change sadly.

Anyway, I don't think its just rangers or focuses that are sensitive to voltage.

Seems like with all the tech all cars have these days have to rely on a battery performing 100% at all times. I even wipe down my battery once in a while so stays clean and no chance of resistance from dirt biildup.

 

[got3fords]

My coworker's '12 Focus just had to have the blend door fixed. It has 180k+ on it.

 

[Jason B]

The blend door problem on the '19 was a physical problem of the plastics warping and jamming the door, sometime the linkage would break. I think for the most part that design problem was fixed.
And no doubt about sensitive to voltage drops. With all the electronics on vehicles, low voltages cause all kinds of problems.

 

[Wang.S]

So I am still dealing with the AC issue.
The battery is an issue on its own, but likely a wrong turn overall.
I'll likely swap it out in the near future, but in the mean time its running a solar charger to keep it topped up.

What I have been noticing since, is when the car is cool on the interior, like parked overnight in the underground, the AC functions pretty good. When its parked in the hot sun, windows up and scorching inside, the AC just blows warm air.

At this point I'm thinking its the temp/humidity sensor. I have no way of testing it, tools or skills wise, just a hunch. It was dirty, I cleaned it, saw some improvement. But I am thinking its still not functioning correctly.

I drove the car yesterday for over an hour, and went from cool air at first, to hot air stuck in traffic, to siberia like icy cold blast the last 20 minutes of the trip.

Anyone have experience with failed or failing temp/humid sensors? does this description fit the bill?

 

[airline tech]

A quick look at the manual for the Focus, it appears near identical (climate control) wise.
There are a number of things that can be at fault. You would need to see if any codes are being generated with scan tool.
Now I noted that it is more noticeable when Hot and, In the Sun.,
2 (things) the Humidity Temp sensor has a small fan on it that blows input air across the sensor, plus there is a Sun load Sensor that ties into this system control.
The Sunload sensor has double duty as it also control's (Auto) headlights.
The sensor measures sun intensity (light) and drives down temp adjustment (to maintain-selected temp) and also forces blower motor to operate at higher speed until normal temp control can be maintained.
This is why if you get into your Ranger and Interior is (HOT) - if you have it in Automatic Control and a low temp selected (say 68 deg) the blower motor immediately jumps to high speed, as it is trying to get to the selected temp (68 deg) faster. The output (discharge) air will be the coldest it can provide.
As you near (68 deg) the blower motor speed lowers and the output (discharge) air will readjust to a temp that will try to maintain the selected 68 deg

There are other sensors in the system but by your posted issue, I am thinking one of the above sensors. (Temp-Humidity or Sunload)

 

[Wang.S]

A quick look at the manual for the Focus, it appears near identical (climate control) wise.
There are a number of things that can be at fault. You would need to see if any codes are being generated with scan tool.
Now I noted that it is more noticeable when Hot and, In the Sun.,
2 (things) the Humidity Temp sensor has a small fan on it that blows input air across the sensor, plus there is a Sun load Sensor that ties into this system control.
The Sunload sensor has double duty as it also control's (Auto) headlights.
The sensor measures sun intensity (light) and drives down temp adjustment (to maintain-selected temp) and also forces blower motor to operate at higher speed until normal temp control can be maintained.
This is why if you get into your Ranger and Interior is (HOT) - if you have it in Automatic Control and a low temp selected (say 68 deg) the blower motor immediately jumps to high speed, as it is trying to get to the selected temp (68 deg) faster. The output (discharge) air will be the coldest it can provide.
As you near (68 deg) the blower motor speed lowers and the output (discharge) air will readjust to a temp that will try to maintain the selected 68 deg

There are other sensors in the system but by your posted issue, I am thinking one of the above sensors. (Temp-Humidity or Sunload)

Thanks, I appreciate your insight, you're like an electron god for us who only know what jamming a knife in a toaster does.

I'll look into the sun sensor. See what I can figure out with it.
The humidity sensor is easy to get at, takes a few minutes to change.

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