Air conditioning died suddenly today...help!

[Emt1581]

Was driving to lunch, air was ice cold and worked fine. No hint of any issues. On the way back, nothing but hot air no matter how long I let it warm up or how many settings I tried.

I usually turn my own wrench but haven't needed to do anything mechanical on this vehicle (2017 GT w/ PP). From what I shared, any suggestions on what could go THAT quickly and where to check for problems?

I can take it to the dealer if all else fails but it's only under the 5 year powertrain, and nothing will be covered.

EDIT: I tested the refrigerant line....plenty of pressure and freon in it.

Thanks!!

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[2018Creamsicle]

Was driving to lunch, air was ice cold and worked fine. No hint of any issues. On the way back, nothing but hot air no matter how long I let it warm up or how many settings I tried.

I usually turn my own wrench but haven't needed to do anything mechanical on this vehicle (2017 GT w/ PP). From what I shared, any suggestions on what could go THAT quickly and where to check for problems?

I can take it to the dealer if all else fails but it's only under the 5 year powertrain, and nothing will be covered.

Thanks!!

Since you didn’t mention seeing a cloud of refrigerant and oil right before it failed, I’ll assume you didn’t have a catastrophic failure in the refrigerant circuit. Since it happened suddenly and was working fine before, that tends to rule out a slow leak or clogged up filter.

Are you getting good airflow inside, or is it weak? Pop the hood with the car running and the AC on max. Is the electric condenser fan in front of the radiator running? Can you see the compressor pulley? Is the inner part turning?

From your description, your problem is most likely electrical. Probably the high pressure switch, low pressure switch, bad condenser fan relay or motor, or bad compressor clutch or clutch relay.

Have you tried running a scan tool or Forscan? I’m pretty sure you can see suction and discharge pressure and temperature in the PIDs you can view on a scanner. Knowing those values would help troubleshoot the problem. Now is just a guessing game.

 

[pyrophilus]

Since you didn’t mention seeing a cloud of refrigerant and oil right before it failed, I’ll assume you didn’t have a catastrophic failure in the refrigerant circuit. Since it happened suddenly and was working fine before, that tends to rule out a slow leak or clogged up filter.

Are you getting good airflow inside, or is it weak? Pop the hood with the car running and the AC on max. Is the electric condenser fan in front of the radiator running? Can you see the compressor pulley? Is the inner part turning?

From your description, your problem is most likely electrical. Probably the high pressure switch, low pressure switch, bad condenser fan relay or motor, or bad compressor clutch or clutch relay.

Have you tried running a scan tool or Forscan? I’m pretty sure you can see suction and discharge pressure and temperature in the PIDs you can view on a scanner. Knowing those values would help troubleshoot the problem. Now is just a guessing game.

This is a great reply! So many things that the OP can check. I eas hoping to post, but thurs replies covers most of what I was going to say, and then some.

 

[IPOGT]

Bad evap coil. Possibly. Known issue 2015-2017. One day warm air. Added dye to evap, found leak, Ford replaced after warranty deductible.

 

[Rock&Roll]

Same thing happened to my car. One day it worked one day it didn’t. A quick look under the hood and nothing leaking and everything looked good so…

Brought it to my Repair Shop and it was the AC compressor. $1100

They recommend I bring it back 2 weeks later to test the system and everything was good. AC works great now.

Sucks that it happened but what you gonna do ?

 

[saleen367]

Don't forget to check the fuse and relay.

 

[Emt1581]

Don't forget to check the fuse and relay.

Just checked and did everything suggested in the vid.

Checked both fuses interior and exterior
Tested and swapped horn relay
Swapped horn and A/C relay and tested the horn.
Used tip of needle nose to manually activate compressor engagement
Tapped on A/C relay
Looked at the A/C engagement NOT running when A/C was not running
Looked at the A/C engagement RUNNING when A/C WAS running


Still get ambient temp air. I'm getting the impression the cost of repair just went way up.

Right now I'm thinking some critter or fluke occurrence caused the freon to leak out or the compressor is shot....but how would it engage on demand if it wasn't functioning? ....so back to the coolant line. I think I have a gauge to test the coolant level but I have to take a look and, if not, buy one.

EDIT: Got a gauge to test the coolant level. Won't have time to hook it up to the low side until after work.

Thanks for the vid!

 

[Emt1581]

Since you didn’t mention seeing a cloud of refrigerant and oil right before it failed, I’ll assume you didn’t have a catastrophic failure in the refrigerant circuit. Since it happened suddenly and was working fine before, that tends to rule out a slow leak or clogged up filter.

Are you getting good airflow inside, or is it weak? Pop the hood with the car running and the AC on max. Is the electric condenser fan in front of the radiator running? Can you see the compressor pulley? Is the inner part turning?

From your description, your problem is most likely electrical. Probably the high pressure switch, low pressure switch, bad condenser fan relay or motor, or bad compressor clutch or clutch relay.

Have you tried running a scan tool or Forscan? I’m pretty sure you can see suction and discharge pressure and temperature in the PIDs you can view on a scanner. Knowing those values would help troubleshoot the problem. Now is just a guessing game.

Air flow is fine. No weakening. Yes, inner part is turning on the pulley when the A/C is turned on. It's still when not turned on.

Didn't run an OBDII which is the only tool I have but it's not throwing any codes so that won't do.

I really don't want to take it to a dealer....yet. Anything else to check?

Thanks

 

[Emt1581]

Bad evap coil. Possibly. Known issue 2015-2017. One day warm air. Added dye to evap, found leak, Ford replaced after warranty deductible.

How do I check/test this?

Thanks

 

[vernonator]

Had a similar incident on my 2016 it ended up that the test schrader valve on the freon line failed and vented the freon. Was covered under warranty at that time, but if I recall it was a fairly inexpensive fix (did need a full recharge)

 

[Emt1581]

Had a similar incident on my 2016 it ended up that the test schrader valve on the freon line failed and vented the freon. Was covered under warranty at that time, but if I recall it was a fairly inexpensive fix (did need a full recharge)

Just tested the refrigerant line....gauge showed it was slightly over pressured. But has pressure and freon in it....so does that eliminate the refrigerant/line and eval coil as an issue or no?

What can I check next?

Thanks!

 

[2018Creamsicle]

Since the compressor is running and you have pressure in the lines, it’s probably not a leak or Freon problem. Doubt it would set any codes you could read on a basic code scanner. You need a more advanced scanner or forscan to read the PIDs that would be helpful.

The big line that goes through the firewall and to the suction side of the compressor should be cold to the touch and should have condensation on it. Be careful with the smaller line on the compressor. It can get hot enough to cause a mild burn.

Without pressure or temperature readings, it’s hard to be more exact, but it almost sounds like you have a broken blend door or blend door actuator, especially if the suction line is getting cold. The blend door is a plastic damper that blends hot and cold air to control the temperature. It’s a fairly common thing for them to break.

 

[Emt1581]

Just got off the phone. He said, typically, once the evap coil goes the freon/pressure is also gone so that fact that mine is in tact all but eliminates that as a possible issue. Also told me, beyond what I've checked it could just be "tapping on the compressor to get it to function again, disconnecting the battery and reconnecting" and "checking actuator movement and the control module" which is what THEY would do for $160.

Anyone have ANY ideas how to "check the actuator movement and/or control module"???

Thanks!

 

[Emt1581]

Since the compressor is running and you have pressure in the lines, it’s probably not a leak or Freon problem. Doubt it would set any codes you could read on a basic code scanner. You need a more advanced scanner or forscan to read the PIDs that would be helpful.

The big line that goes through the firewall and to the suction side of the compressor should be cold to the touch and should have condensation on it. Be careful with the smaller line on the compressor. It can get hot enough to cause a mild burn.

Without pressure or temperature readings, it’s hard to be more exact, but it almost sounds like you have a broken blend door or blend door actuator, especially if the suction line is getting cold. The blend door is a plastic damper that blends hot and cold air to control the temperature. It’s a fairly common thing for them to break.

Thanks for the info. How would I test/check this?

Thanks

 

[2018Creamsicle]

Thanks for the info. How would I test/check this?

Thanks

The blend door actuators are what they were talking about I think. It’s up under the dash. They are small electric stepper motors or vacuum actuators. I’ve never had an S550 dash apart, so I’m not sure where they are exactly. Try this thread. https://www.mustang6g.com/forums/th...re-all-three-blend-door-actuators-are.113633/

You could still have an electronic issue. It would be really helpful to get a look at the climate control PIDs to get a better idea whats going on.

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