2020 AC Not Blowing Cold

[ERNursebev72]

Hello There!

About a week ago, the battery died. I had it charged back up and it started fine. But now the AC is not blowing cold. It was working perfectly fine prior to that - blowing cold and hard air.

Issue:
Blowing and hearing compressor click. No cold air. Also a increase/decrease in fan speed on deceleration/acceleration.

Things checked:
Reset the BMS
Reset the SYNC system
Pulled out Fuse 32 that belongs to AC Clutch - intact

I am looking at the fuse diagram and don't see anything else that is obvious that could be AC.

I am a nurse so I can help bring people back to life, but I am also a woman. I prefer to try to figure these things out on my own before taking it to a mechanic and spending more than I need to.

It has 60K miles no previous issues.
Engine 3.5L GTDI

Ideas?

 

[99WhiteC5Coupe]

Hello There!

About a week ago, the battery died. I had it charged back up and it started fine. But now the AC is not blowing cold. It was working perfectly fine prior to that - blowing cold and hard air.

Issue:
Blowing and hearing compressor click. No cold air. Also a increase/decrease in fan speed on deceleration/acceleration.

Things checked:
Reset the BMS
Reset the SYNC system
Pulled out Fuse 32 that belongs to AC Clutch - intact

I am looking at the fuse diagram and don't see anything else that is obvious that could be AC.

I am a nurse so I can help bring people back to life, but I am also a woman. I prefer to try to figure these things out on my own before taking it to a mechanic and spending more than I need to.

It has 60K miles no previous issues.
Engine 3.5L GTDI

Ideas?

I’d bet you have a bad battery and/or loose or corroded battery terminals and connectors.

 

[ERNursebev72]

The battery is brand new - Dec 2023. Terminal and connectors clean.

 

[99WhiteC5Coupe]

The battery is brand new - Dec 2023. Terminal and connectors clean.

You reported that the battery died - there has to be a reason that happened.

It is not brand new, it is six months old and has died once.

 

[ERNursebev72]

It died because it got drained from a secondary battery onboard that runs a refrigerator that gets charged when running my vehicle from the alternator. I was supposed to turn it off when I parked for a week and forgot. So once the onboard battery died - it started running off the car battery and depleted it. Once it was jumped off, they are both working fine. The ford battery is only 6 months old and was purchased new.

 

[ERNursebev72]

If the battery is cranking now and the blower and compressor are running fine - how can the battery be the problem? Just trying to link it all together.

 

[bmk1]

Are you outside of warranty?

 

[VCFP153]

Hello There!

About a week ago, the battery died. I had it charged back up and it started fine. But now the AC is not blowing cold. It was working perfectly fine prior to that - blowing cold and hard air.

Issue:
Blowing and hearing compressor click. No cold air. Also a increase/decrease in fan speed on deceleration/acceleration.

Things checked:
Reset the BMS
Reset the SYNC system
Pulled out Fuse 32 that belongs to AC Clutch - intact

I am looking at the fuse diagram and don't see anything else that is obvious that could be AC.

I am a nurse so I can help bring people back to life, but I am also a woman. I prefer to try to figure these things out on my own before taking it to a mechanic and spending more than I need to.

It has 60K miles no previous issues.
Engine 3.5L GTDI

Ideas?

Interior temp sensor?

 

[99WhiteC5Coupe]

If the battery is cranking now and the blower and compressor are running fine - how can the battery be the problem? Just trying to link it all together.

I have seen many batteries damaged from being discharged fully, then jump started and / or charged.

Years ago, batteries lasted a long time and could be repeatedly discharged and recharged, and keep going. No longer.

You may have a damaged cell that is causing intermittent electrical issues. New vehicles (loaded with sensors, computers, modules, etc.) are very sensitive to battery issues.

I wish you luck. Keep us updated on what you determine.

 

[ERNursebev72]

Went to AutoZone and replaced the battery today. Still no cold air

 

[99WhiteC5Coupe]

Went to AutoZone and replaced the battery today. Still no cold air

You said earlier that you charged the original battery (that died). Did your jump-start the vehicle’s engine when it had a dead battery (perhaps causing electrical damage)? Have you scanned the vehicle for any stored trouble codes?

 

[LegalBrief]

The trucks have AGM batteries, once they are completely discharged they have to be replaced. Some weird test manufacture requires takes 4 hours if your trying to get it under warranty. If you want software updates the AGM must test above 50%, or update won’t run, that mean you may get a new battery as part of the software update. @ERNursebev72 go to dealer, you are at or near end of your warranty, you won’t fix this yourself.

 

[GaryH]

Is the AC compressor clicking on and off rapidly every few seconds?

 

[Galaxieman]

Just had a very similar issue: 2019 Max Limited. Went on vacation for 10 days, battery wasn't fully discharged, but after it sat for the 10 days the AC blew external temp air. Checked blend door operation by switching to heat, and it blows HOT, so that's not the issue. Checked the refrigerant at the low-side port and it read low, so I put part of a 12-oz can of R1234YF in, and it's up in the green for pressure, but still only blowing 'cool(ish)', vice ice-cold like it did when we parked it.

Next steps for me, and what you might look into:
-I have a set of A/C line gauges on order, so I'll be able to see the static pressure on both sides when the compressor isn't on, then both the high and low pressures when the compressor is on. Gauge on the fill adapter shows ~110psi on the low side w/o the compressor on, and ~40psi (mostly guessing since the gauge isn't marked very well) on the low side with the compressor running. I went ahead and ordered the gauges so I can check both sides simultaneously when the compressor kicks on to see if it's over-filled.
-I need to check on the active vent shutter operation to see if they're staying stuck closed when the truck is on. With zero air-flow, it would pretty much kill any ability of the radiator or condenser to dissipate heat.

Interested to see what other steps you take to see if any of them fix the problem.

 

[willtd14]

Random temp fix it happens on my 2018. What works best for me is turning the rear AC on even if no one is there and front AC runs cooler. Sometimes randomly driving the AC gets really cold!

 

[T Bird]

Did you check refrigerant level?

 

[99WhiteC5Coupe]

Went to AutoZone and replaced the battery today. Still no cold air

What have you resolved or determined?

 

[Mr Big]

Hello There!

About a week ago, the battery died. I had it charged back up and it started fine. But now the AC is not blowing cold. It was working perfectly fine prior to that - blowing cold and hard air.

Issue:
Blowing and hearing compressor click. No cold air. Also a increase/decrease in fan speed on deceleration/acceleration.

Things checked:
Reset the BMS
Reset the SYNC system
Pulled out Fuse 32 that belongs to AC Clutch - intact

I am looking at the fuse diagram and don't see anything else that is obvious that could be AC.

I am a nurse so I can help bring people back to life, but I am also a woman. I prefer to try to figure these things out on my own before taking it to a mechanic and spending more than I need to.

It has 60K miles no previous issues.
Engine 3.5L GTDI

Ideas?

If all fuses were checked and still no cold air, it could be low on refrigerant, bad AC compressor clutch, vacuum issues, control panel?
Is your AC light on at the dash controls? Does MAX AC make any difference? Do you hear the compressor engaging under the hood, and if visible, can you see the clutch engaged? If possible, when you put your hand around the fat AC pipe is it cold?

 

[Galaxieman]

Update on wife's rig: Rear evaporator was done, and needed replacing. Got a good recommendation for a local shop (NOT a dealership since it's out of warranty), and got a new rear evap installed for right at $1,100. Front evaporator would have been more expensive (take apart the dash? ugh!), followed by the compressor. Shop guys were in agreement that the new R1234YF is not any great 'improvement' over the R134A, but is just more expensive.

All-in-all having a trusted shop look at it (after ruling out all the cheap options) is really the way to go.

 

[Tom991]

Update on wife's rig: Rear evaporator was done, and needed replacing. Got a good recommendation for a local shop (NOT a dealership since it's out of warranty), and got a new rear evap installed for right at $1,100. Front evaporator would have been more expensive (take apart the dash? ugh!), followed by the compressor. Shop guys were in agreement that the new R1234YF is not any great 'improvement' over the R134A, but is just more expensive.

All-in-all having a trusted shop look at it (after ruling out all the cheap options) is really the way to go.

I'm having a similar issue on my 2020 Expedition. I was driving suddenly the AC began blowing hot. All the refrigerant leaked out. I took it to a shop they flushed the AC filled it up with 134A with dye in it. The mechanic told me to drive it for a week and bring it back and they'll take a light that will illuminate the dye and look to see where the leak is. I asked about the 134A refrigerant. He told me the 134A is compatible with the AC system. Also the R1234YF is corrosive and after a while will damage the AC system. So after my system is determined that it has no leaks or is fixed they're going to refill it with 134A. It's 1/3rd the price of 1234YF and is not corrosive. I wonder who came up with the idea of using a product that can destroy the AC system and cost triple the price of tried and true refrigerant?