Ok, got one lung and I am particularly sensitive to how good an a/c is working in a vehicle. I have a 2005 F150 KR, 5.4, 103,000 miles. The dealer sold me on a new (re-furbished) a/c compressor after having "checked out the system". $900 later and I was still complaining. This was the first time I have ever had to change out a Ford a/c compressor! So they shoved a thermometer into the a/c duct and told me it was within the the specifications. Bang my head against the wall! I get into my all black with black interior F250 (in Florida sun/heat mind you) and after just 3 minutes that interior is cool enough for me to start driving with that sun glaring down at noon. Got into the vette, same great results after only 3 minutes! In fact, out of the 10 vehicles I have tried, (7 were Fords) they all beat out my '05 King Ranch. Now mind you, the F150 KR had at one time unbelievably excellent a/c... til it one day, just quite wasn't working good enough for me to handle the Florida heat.
We already had at one time brought it in because of some sound under the dash like a creaking door opening real slowly but no one could diagnose that.
So I am now into my third summer and refuse to have to park it because of the a/c situation. I have decided that I should change out the blend door motor (which is what I had asked them to start with in the beginning).
I figure it's already in my garage for oil change, tire rotate and installed a set of new spark plugs (...and no, I did't break any. I bought that tool {$$$}... and that's why non broke!!) and am going to install a new blend door motor. I just would like to get some of you Ford truck owners' opinions..... have any of you had this a/c problem where the blend door motor was the culprit??!! Thanks. SC150 4nanart3@gmail.com

 

Hi! and welcome to FTE my friend, I moved your thread to a proper Chapter in order for you to get some answers, I hope you solve your A/C problems.

 

All black with black interior in a KR and living in Florida eh? You must be a bear for punishment. Anyway to your question although I don't have the KR just the lower version XLT The blend door on mine creaks and groans like a Halloween door and as long as I can hear it I know the blend motor is working.

Believe it or not we get some insane heat here in Canada as well but not the duration you get.

Anyway what I've done to cool things off quickly is crack the windows open at least half way and crank on the blower with the Max air on for a couple minutes.

Switch the blend to recirculate that way you are cooling air that's already been cooled off instead of trying to cool air brought in from outside then close the windows almost to the top maybe leave 1/4 inch.

My theory is if the windows are closed the blower would, for example try to blow air into the cab like a ballon that's already full of air, give it a little escape and things cool off great.

If they shoved a thermometer up its vent and said its good for cold then just let it breath a little.

I don't think you really want to tackle that blend motor job cause from what I understand it's a real long and frustrating job, check it out before you go getting into it yourself.

Hope this was some help

Cheers From Studio48 London Canada
Law of mechanical Repair: After your hands become coated with grease, your nose will begin to itch and you'll have to go pee

 

sc150
I think that you are on the right track. I do hear my blend door opening and closing in my truck. I bought my 06 f-150 2wd 5.4 three years ago with 37K on the clock. when I first got it the air was not that cold out of desperation and with little cash to spend I bought one of those charge cans with gauge from local shop for $30 or so. It did not improve anything so I just decided to live with it. The first winter I forgot about the ac issue and it was June or so the next year before I realized that the ac was working great. I have come to believe that it must have been the blend door and as I used the heat and adjusted the temp (which I never do in the summer) for a mild winter here in SC must have loosened up whatever was causing the hang up. I have gotten into the habit of turning it from hot to cold every so often just to make sure she stays cool. I used to work new construction in Tampa and know that between the temp and humidity ac is a must! Good Luck and congrats on the plugs. Shawn

 

The blend door actuator is a very easy job. The only hard part about it that there isn't much room to work. If you have small hands you are in pretty good shape.

 

Have had to replace my blend door actuator three times ('06 Lariat, electronic temp). The dealer did every time, so I cannot firsthand tell you about the process, however, I believe the flat rate manual specifies only 0.5 hours, so it must be fairly easy. I know for a fact that it only took the tech <1 hour to complete. Still cost me >$300 the one time I had to pay (twice under warranty).

 

Write up on how I made my not so great A/C a little better. - Ford F150 Forum - Community of Ford Truck Fans

Helped out mine quite a bit.

Also if you have a cabin air filter I would change that for sure. You also might want to look into your evaporator, the one by the heater core to see if its full of gunk.

 

I did the blend door motor. Unbelievable super simple and quick job. 30 minutes tools out, exchange, tools away and vacuum the area clean. Unfortunately, a/c still a weak cooler. Time to bring it to an a/c specialist to see if a it'll take some more freon. My F250, Caddy and vette all produce 62 degree vent temp in under 3 minutes in the brutal Florida sun. The KR only gets down to 67 and the dealer accepts this as good! The just won't accept the idea that it was better than that for 6 1/2 years!! They just don't want to re-do it. Politics of the dealership... between front office and shop!!!! And they wonder why I buy my fords at a different dealership. I keep giving them the chance to make good. Oh well... time to drive a distance.

 

I read about a mod where the writer inserted an H with valves to bypass the heater core in summer, but to be able to use in winter. Was claimed to have helped greatly.

 

I wonder if they put too much oil in the system. Too much oil can cause poor performance. Some compressors come with oil already in them and need some drained depending on what all is being replaced.

 

Too much refrigerant will also cause a problem, potentially causing it to enter the compressor in liquid form (incompressible), degrading performance and potentially failing the compressor. I read the pressures unknowingly without the clutch engaged, thus thinking I needed more refrigerant. Added too much and performance suffered. Later realizing my mistake, I extracted some of the refrigerant and the air was much colder.

 

That's a very good point! I have actually ran into that problem before but forgot until you brought it up. The parts store "helped" someone out by adding refrigerant.

 

With 100,000 mi, I would look into changing the fan clutch, because that is one of the most problems with these trucks... if its not pulling through enough air, its not gonna blow cold wen in city or idling. Another thing u can do is to clean the evaporator core under dash. Since its a king ranch, remove the fan resistor under dash, and that will allow u to wash out the evaporator with a water hose gun at low preasure.. Trust me its full of dust and crap. JUST BE VERY CAREFULL NOT TO SHOOT WATER ALL OVER THE PLACE UNDER DASH. DO THIS AT UR OWN RISK.,, but it can be done. this can be done with trucks with eatc, because the fan resistor is huge and the opening allows you to fit a water gun hose in there... On the manual ac its very small opening. Just don't spray the fan, only where evaporator is. I used my phone camera to shoot pics of the inside of the evaporator , then I knew where to spray it with water. Hope this helps, infact I know it will help at least with cleaning and getting any smells outa there.

 

There are many things you can check and do to troubleshoot an AC system. the first thing is to determine if the compressor is working. Simply start the truck, raise the hood and observe the compressor with the AC on 'MAX'. It will cycle on and off, which is normal, but on a hot day it should be more 'on' than 'off'. Assuming it's hot and humid when you do this, now look at the suction line (larger pipe) where it enters the compressor - it should be sweating and it should feel cold. So far, so good - the system is basically working.
Next you observe the air flow from the registers inside the vehicle. Get in and shut doors/windows. Set fan on highest speed and hit the 'MAX' or 'RECIRC' button. Set the distribution of air to 'dash only'. Give the engine enough throttle to get and hold 2000 RPM. Fan should be blowing very hard and the air should be blowing with force from the dash registers. After 5 minutes, take the temperature of the air at the center register - a probe-type thermometer is good for this. Give it at least 2 minutes to fully chill before reading. Once you get the temp, subtract it from the outside temp to get the temperature drop which should be around 35F-40F. So if it's 95F outside, you should be getting about 55F-60F air in the truck. But you have to use common sense too - if it's 65F outside you would not expect 25F air to blow out. I have seen the air temp approach 35F in some cars but that is an extreme case that could cause the evaporator to ice over.
I haven't seen anyone mention here about cleaning the condenser or making sure the belt is not slipping on the compressor. Also, cars with automatic climate-control systems automatically blend heat with the cold after only a few minutes of operation to prevent the occupants from being chilled by frigid air. The test here is simple; does the system meet the temperature you have set, as long as it is a reasonable expectation? IOW, if you set the temp at 72F (which is comfortable for you) and it's 95 outside, the auto system will set 'RECIRC', highest fan speed and probably 'dash only' registers. After only a few minutes it will reset parameters as-needed, including delivered air temperature/force, to maximize comfort and minimize noise.
The 2005 F-150 does not have a cabin air filter. My 2007 doesn't either, but it needs one.

 

Interesting post, I have a similar issue with my 08. Mine does this: randomly you can feel the air go warm, but the compressor is still engaged. Sometimes it will switch back quickly, other times takes awhile. Does not do this if traveling down the highway on a trip. Does this in either auto or non auto mode. I keep the truck on recirc.

Actions taken: had system vacuumed and FOV replaced and weight charged, same issue. Have replaced blend door motor.