A/C blowing hot air

[eGuru]

11 hours ago, 86SVOwner said:

I have the same issue where having the headlights on allows the air to continue to run cold. Must be an electrical issue...voltage, resistor?!? Any ideas?

 

It would be beneficial if you could give more details about the symptoms and any tests you have performed. This is a long thread from many contributors with various problems so saying "I have the same issue" is not precise enough for the members to help you with accurate/useful suggestions.

 

You haven't told us your MY and type of HVAC control.

[86SVOwner]

2012 SE, 4 cyl, Manual controls, 95,000 miles. Turn on the ac, starts out real cold then after about a minute it goes to full heat. Will not go back to cold unless the engine is shut off then back on. Fuses are all good. Relays for backup lights and compressor are same so I swapped them, no change. I had a similar problem with a Toyota and it was a relay. Found on this thread someone was able to keep the air working by having the headlights on. Figured that was an easy test. Started the car, turned on the headlights, turned on the ac and went for a long ride. All was nice and cool until I turned the headlights off. Within I minute it starts blowing hot air. Pulled over, repeated the process and got the same result.

 

This began yesterday when my wife was driving home from her client’s office. I told her to try the headlight trick when she headed out for the day today. She said it worked like a champ.

 

While searching other similar threads a couple guys commented that theirs blew cold early morning and at night but not during the day. I’m guessing they had their headlights on when it was working.

 

Obviously some type of electrical/electronics issue. Don’t want to spend lots of $$$ for diagnostics and trial and error if someone here has a solution or reasonable suggestions. I’m new to this forum and I appreciate your help.

[Artem]

I had similar issues when a/c was working for 1 minute and than go to heat. 

Went to junkyard and bought 2 HVAC controllers for ~20$ each. Install the fist one and resolved my issue, the second one did not even try.

[eGuru]

13 hours ago, 86SVOwner said:

2012 SE, 4 cyl, Manual controls, 95,000 miles. Turn on the ac, starts out real cold then after about a minute it goes to full heat. Will not go back to cold unless the engine is shut off then back on. Fuses are all good. Relays for backup lights and compressor are same so I swapped them, no change. I had a similar problem with a Toyota and it was a relay. Found on this thread someone was able to keep the air working by having the headlights on. Figured that was an easy test. Started the car, turned on the headlights, turned on the ac and went for a long ride. All was nice and cool until I turned the headlights off. Within I minute it starts blowing hot air. Pulled over, repeated the process and got the same result.

 

This began yesterday when my wife was driving home from her client’s office. I told her to try the headlight trick when she headed out for the day today. She said it worked like a champ.

 

While searching other similar threads a couple guys commented that theirs blew cold early morning and at night but not during the day. I’m guessing they had their headlights on when it was working.

 

Obviously some type of electrical/electronics issue. Don’t want to spend lots of $$$ for diagnostics and trial and error if someone here has a solution or reasonable suggestions. I’m new to this forum and I appreciate your help.

Probably the HVAC control module. Easy to find on eBay or recycler - not expensive and easy to install.. No dealer programming required.

If that doesn't solve it, I would replace the blend door actuator - also a simple DIY and an inexpensive part.

 

Of course, ideally we would use an OBD2 interface and FORScan and perform more diagnosis instead of "throwing parts at the problem" but those items are the most frequent failure items.

 

Keep us updated on your progress.

[pencema]

Lots of interesting tricks to try!  I have an 06 SEL, V-6 with automatic temp control.  The A/C started getting a little weak last fall, and more so this spring.  But turning the temp down got pretty cold air and higher fan speed (as expected).  Then a week or so back, I got nothing but hot air.  Thought the freon might be low, and I had a can of R-134A and a charging hose, so I put it in.  The compressor came on after charging for a minute or so, and cold air started blowing from the vents.  Problem solved - I thought.  However, since then, no A/C at all.

 

I bought a gauge and more freon, and added about half a can.  The gauge read nothing when I started, but came up to the upper end of the green (good) band, at which point I quit charging.  However, the compressor still wouldn't come on, and I got no cold air.

 

I have am OBD-II code reader, but get no trouble codes.  I'd expect one (P 5038?) if the Evap Temp sensor was bad, right?  Checked fuses - all good.  Even tried pulling the battery cable to reset the PCM, and then turning on the lights.  Nothing helps.  Still hot air.

 

For clarity - it's not hot air as if from the heater.  Just outside air, which right now is pretty warm.  Early morning, it's okay, just not refrigerated air.

 

I had an issue that I believe was related to the PCM, where the engine would slip into "limp" mode (3 cylinders) at highway speed.  I changed the plugs and that problem has gone away.  But I'm suspicious of the PCM, since it's involved in both problem situations, and I get no trouble codes.  Any ideas?

[pencema]

I tried disconnecting the battery, and running with lights on, but nothing worked.  Finally took it to a shop (AAMCO, Gaithersburg, MD) and they found a leak in a high pressure hose.  None available today, but will take it back Monday for repairs Tuesday.  Fingers crossed!

 

[Fishcampsteve]

We have a 2010 Ford Fusion that the A/C would blow cold air then turned to hot air from the like the heater.  Had the freon checked is was good.  Changed the blendor door actuator and that worked for a couple of days then the A/C started blowing hot air again.  Researched this thread and decided to try the headlight trick and it worked!!  Turned them off one day on the way to work and immediately the A/C started blowing hot air.  Crazy.  Going to go with this for now, but may try replacing the HVAC controller from ebay sometime.  Keeping fingers crossed!

[katashinomo]

This is going to sound nuts, but I saw it on youtube and it worked for me.   Before turning your car on, turn the lights to the ON position (Not auto) and pull the knob out to turn the fog lights on. THEN start your car after that. For some reason when you do this in the 2012 Fusion it makes the AC work properly again. You have to turn your lights on manually every time though. 

[mdjsg]

My 2012 Fusion 2.5L SE started blowing hot from the heater before I backed out of the parking lot.  Found if I turn off the engine and restart it blows cold for 15-20 seconds then blows piping hot.  I put the gauges on and pressures are all good.  The blend door goes from cold to hot for some reason.  Restart the engine it blows cold every time.  But after 15-20 seconds the blend door moves to hot.  I am going to try the headlight thing, the battery disconnect idea, however I will first pull codes and look at the ambient air temp.  Will post what I find in a little bit.

[mdjsg]

Got all pass codes.  Tried the headlamp idea and that did not work.  I moved the temp selector to hot all the way and dialed it back to cold and it worked good.  However if I put it on the coldest setting the temperature blend door moved to hot.  As long as I keep the selector on anything but the coldest setting the AC works perfect.  Probably going to have to replace the control panel and blend door, but we'll see about that later.  I am going to run it a while.  The headlamp idea probably means there is a grounding issue and the module is using the headlamp wiring for a ground somehow.  The car has over 236,000 miles so I should expect something like this.

Edited August 25, 2019 by mdjsg

[eGuru]

51 minutes ago, mdjsg said:

Got all pass codes.  Tried the headlamp idea and that did not work.  I moved the temp selector to hot all the way and dialed it back to cold and it worked good.  However if I put it on the coldest setting the temperature blend door moved to hot.  As long as I keep the selector on anything but the coldest setting the AC works perfect.  Probably going to have to replace the control panel and blend door, but we'll see about that later.  I am going to run it a while.  The headlamp idea probably means there is a grounding issue and the module is using the headlamp wiring for a ground somehow.  The car has over 236,000 miles so I should expect something like this.

Just replace the blend door actuator. It sounds like it has a dead spot on the position feedback pot.

 

 

[mdjsg]

Replaced the blend door motor and all is well so far.

[DeAnn]

On 8/4/2017 at 12:03 AM, GRakka said:

On my 2011 Fusion the AC would work and then start blowing hot air. Turning the car off and on again will get the a/c to work again but no guarantee on how long it would work. It seemed that if I turned on the light and then turned on the AC (and keeping the lights on), the AC would work the whole time. With help from this forum, the issue was narrowed down to 1. Blend Door Actuator 2. EVAP Temp Sensor 3. HVAC Control Module. Since the blend door was the easiest to get to, I replaced it first but it did not resolve the issue. I was able to get OHP Ford ELMconfig USB device from Amazon for about $30 and using Forscan software on a laptop I was able to rule out the evap sensor. I did not want to spend over $200 for a HVAC control module and was able to buy used on ebay for $30. Replaced it and my a/c has worked perfect since. Hope this helps.

 

BTW - if you are going to replace the HVAC module, look up youtube videos on replacing the radio on your Fusion. The video provides instructions on how to remove the bezel.

I tried leaving my lights on also, and it worked! I ordered the hvac control module from EBay, but they sent the wrong one, and I had to return it. In the meantime, I had another issue arise. The idler pulley was bad, causing the serpentine belt to slip, so I replaced it and the belt. Low and behold, the ac works again. Just putting this out there, in case anyone is still having this issue. 

[NullPointer]

I had issues with charging system prior to the issue and removed + terminal for 30s and it fixed it. It reset the temp sensor I was told.

[eGuru]

10 hours ago, NullPointer said:

I had issues with charging system prior to the issue and removed + terminal for 30s and it fixed it. It reset the temp sensor I was told.

The HVAC controller "re-learns" the physical end of travel positions for the actuators when you perform this type of reset. The temperature sensors are not "reset".

[jBers]

On 7/15/2015 at 7:54 AM, KLB33 said:

I am having issues with my AC. Went out (blew hot air) intermittently for a while, then started always blowing hot air. I had my mechanic check the compressor (running correctly at about 250/40) and the freon (had a minor leak that was fixed). After searching online and the forum, we decided it was probably the evap temp sensor. My mechanic was unable to change it, so a friend and I changed it. The air blew cold that night after changing it, but then started blowing hot again the next day.

 

I then searched the forum some more and found the issues with the blend door actuator. Somewhere (I was researching for a LONG time) I saw a statement to turn the air knob all the way to hot, and click by click turn it to cold. This works temporarily.

 

I am searching of any advice on if it does sound like it might be the blend door actuator. If so, if anyone possibly knows which actual part I would purchase. The parts on the Ford website are listed as the blend door motor cam, blend door motor level, blend door motor temperature mode actuator and blend door motor air inlet (recirculation).

 

Or, perhaps someone has an idea of something else it could be!

 

Any help would be greatly appreciated as at this time, I simply can't afford to take it to the dealership.

 

Thanks in advance!!!

 

2010 Ford Fusion - Cold air for about 15-30 seconds then it would switch to really hot air each time I start the vehicle.

 

Fixed: Replaced the HVAC Module (A/C switches on the center console). $225 at AutoZone - Dorman A/C Selector Mode Switch 599-228.

Not a difficult job.

 

How-to Video: https://www.youtube.com/watch?v=ThjrCiGtn-A

 

Remove storage compartment on top of the dash, 8mm bolts under rubber mat. Then pry up from the front then forward to remove from the tabs. Must cut safety strap that is attached just under the Hazard Lights Switch.

Remove silver trim ring around Gear Shifter.

Pop up the front of the trim panel around Shifter that makes up the top of the center console around the shifter. Pop up the front by going through the whole where the silver trim ring was. Do not need to remove the entire piece, just the front so you can,

Pop up the charging port/change cup in front of it and remove.

Remove the two 7mm bolts at the top of the radio rack trim panel. They were hidden under the storage compartment that you removed earlier from the top of the dash.

Pry off the entire radio rack/HVAC Module trim panel. Remove the four electrical connectors behind the panel. All release by a push button.

Remove the HVAC Module by removing the four T20 star bolts

 

The other common causes of the A/C acting this way is:

 

1)   Blend Door stuck. Test this by; Turn battery power on but do NOT start the car. Turn on the HVAC power (push the button). Slowly turn the Temp Control knob from Cold to Hot. If the Blend Door is working, you will hear it (humming) as it moves. The sound comes from under the dash, above the gas pedal.

 

2)   A/C Evaporator Temp Probe Sensor. This is the worse one to fix because the entire dash must be removed to replace the $20 part. There is a quick easy workaround by installing a resistor wire between two wires that are going into a multi-plug behind the glove compartment door.

 https://www.instructables.com/id/Quick-fix-workaround-Ford-Fusion-AC-evap-sensor/

 

 

[Fuser]

Found a U-tube video where the guy turned on the fog lights to get the A/C to work after replacing EVAP temp sensor and controls.  Stated that Ford knows about the problem but did not wan to do a recall.

 

https://www.youtube.com/watch?v=kq9InunWkPw

 

This link shows how to bypass the EVAP sensor.

https://www.instructables.com/id/Quick-fix-workaround-Ford-Fusion-AC-evap-sensor/

 

It is weird that turning on fog lights and A/C works but other posts express something similar with headlights.  Would really be nice if the true cause and fix could be revealed.

A friend said the local dealer charges $120/hr.  A working guy with a mortgage cannot afFORD that.