4 years ago I carried my truck to Firestone to get the air conditioner checked out. It blew strong cold air but only if it was turned to maxium air. Below is a copy and paste from that visit of what they recommended:

RECOMMENDED SERVICES NOT PERFORMED

BLEND DOOR ACUTAOR (TEMP)

$293.99

[$83.99] HEAT AND AC ACTUATOR
[$210.00] REMOVE & REPLACE MODE DOOR ACTUATOR


They recommended however that it was not urgent to have it replaced and continue using it as it was. Since i normally only ran it on maximum air anyway I agreed. Last year, however, it stopped blowing cold air out completely so I carried it to another firestone location and below is what they did and how much they charged me:

AIR CONDITIONING
$500.36

[$8.99] ORIFICE TUBE 1 EA TOUGH
[$119.99] AC HOSE ASSY 1 EA TOUGH
[$85.99] A/C ACCUMULATOR 1 EA TOUGH
[$57.00] REMOVE & REPLACE EVAPORATOR ORIFICE VALVE
[$68.40] REMOVE & REPLACE ACCUMULATOR OR RECEIVER DRIER
[$80.00] R134A PER POUND
[$79.99] AIR CONDITIONING 134A SERVICE

Don't really see where they did either of the things listed in the recommendations from 2016. However, I'm not a mechanic so it might be there just under a different wording. Anyway, after I got it back it was blowing very cold air again however it's barely blowing any air through the vents at all. If I stick my hand up to the vent i can feel very cold air. The blower sounds like it's blowing very strong. They told me at the time "you may have something stuck in your vents" and just sent me home with my truck as it was. I paid $500.36 dollars and sweated the entire summer because the air barely blows through the vents. It was blowing much stronger before they worked on it.

I finally carried it back a few days ago to get it rechecked. I can't go another entire summer with no air. They tested everything and are now saying it might be an issue with my heater box and I would need to carry it to a dealer to get them to check it out and they would have to remove the whole dash to do it.

I'm not very mechanically inclined, so I don't if what they're saying is true. Any advice from anyone?

 

Welcome to the forum

There is nothing in the vent tubing that can block air flow, you can select the direction of the air flow, defrost, panel or floor, but air flow can't be blocked inside the cab

Its not uncommon to have Defrost vent get all the air flow, this is a Vacuum problem usually in the engine bay, so with fan on high, and panel selected, see if defrost vent is getting all the air flow, if so then its a vacuum issue

Next step requires you remove the fan motor from the engine bay "heater box"
3 or 4 screws
With fan removed you can see in and reach in to the heater box to see if there are obstructions inside the box
From the fan opening to the right is the AC Evaporator, it is like a mini radiator with small fins that the fan air has to pass thru to get into the cab, it can get debris inside usually from mice
Also check the fan cage and its attachment to the motor's shaft, if its loose then motor is spinning fast but fan is NOT

Yes, try MAX AC
If you get full air flow only in MAX AC then your Fresh air intake is blocked, it is under the cowl in front of windshield

AC is either on or off, it doesn't have two speeds, just FYI
What MAX AC does is to pull air from INSIDE the cab so it doesn't have to cool hotter outside air, there is a vent behind glove box that closes and blocks outside air in favor of inside air going into the Fan, but only used in MAX AC setting
In the old days there was often a manual switch on the dash to select Fresh or Re-circulated air

 

A question i have for you OP is this. Let the car sit for a couple hours. Then hop in and turn the AC on and the blower on full speed right away. Does it come through strong? In other words, does the air flow slow down as time goes on until it basically just trickles out the vents?

Set fan speed to maximum but don't run AC. Do you have good air flow? if so, you can probably rule out a loose fan blade or a bad motor.

I need you to answer these two questions, it is very critical.

Also, please don't go to firestone for anything other than tires. Labor is marked up and usually the techs are hit or miss. Don't go to the dealership too. Basically, firestone and the dealer both want to **** you. Go ahead and find yourself a local mechanic. Ask on facebook, people that are passionate about cars LOVE to reccommend their favorite mechanic, I have mine thats for sure. Go to him and have him service your AC from now on. No more dealership, no more firestone.

 

Sorry to jump in a year late but I was trying to diagnose a problem with my AC in my daughters 2007 FX4 4X4 with a 4.0. What you described is exactly what is happening. The fan was working and sending air to the correct setting when changed, By that I mean it would come out the vents when set there or out defrost when set there etc. The AC was blowing hot air so her boyfriends dad did an "AC recharge" of one kind or another. I don't for sure know what was done as they are in a different city but it was definitely working with the exception of blowing hot air before. She came home in her Ranger and told me that the AC was not working. When I went to check it out, the blower was sounding like it was blowing strong but a very weak air flow was felt in all locations, ( dash vent, floor, defrost) and the rotary dial would not change the air flow. It was hot out and I left it until the morning. I came back the next morning and everything seemed to work fine. Blowing cold(ish) in AC and the rotary dial would change the direction of the airflow, just like normal. So I then left it alone. She drove back to her place and messaged me that the same thing happened again where it was working fine for some time and then did the exact same thing where the blower was blowing weak in all outlets.
Any help you could provide would be helpful.
Thanks

 

Welcome to the forum

You should probably have started your own thread, its free

Vents, i.e. panel, floor, defrost, are all vacuum operated so if you can't change vents then its a vacuum issue

The engine provides the vacuum but its Stored in a Vacuum Reservoir so changing engine vacuum doesn't effect Vent selected, same as power brakes use a Vacuum Reservoir, the big Booster
The Vacuum Reservoir is a Black plastic ball located down low on passenger side of engine bay at the front, its just in front of the passenger side wheel on the other side of the wheel well liner

There is a vacuum line from the engine to this ball
And then another vacuum line from the ball to the firewall on passenger side, there will be two vacuum lines at the firewall a black one from vacuum reservoir and a GREY one from heater hose by-pass valve
It often easier to find the GREY one in engine bay and follow it down to the firewall to locate the black line

Check the black hard plastic vacuum line, it often melts cracks or breaks on its route thru engine bay to the Vacuum Reservoir, can be easily spliced with correct diameter rubber vacuum hose
Or could be the Vacuum Reservoir is cracked and leaks, not uncommon

Reservoir picture here: https://www.ranger-forums.com/attach...0reservoir.jpg
In front of passenger side wheel well

Reservoir with engine bay hoses here: https://www.explorerforum.com/forums...nes-jpg.41662/

The white connector is INSIDE the cab when installed, looks like this from inside: https://imgur.com/AHlTteI
The grey line is only used to shut off flow of hot coolant thru heater core in the cab when MAX AC is selected
Not pictured is the vacuum line from ball to the engine, that should also be checked

Another thing to check is to remove the Blower motor and reach inside to feel the back side of AC Evaporator, this area can get clogged with debris, leaves and such, or NESTS of small critters, lol
In any case that can cause air flow to come and go, as all the air from blower has to pass thru the evaporator to get to the vents


Just FYI
The TEMP **** runs an electric motor called the Blend Door Actuator that's inside the cab behind glove box
If there is no temp control that's a common issue with Fords, blend door actuator fails
This wouldn't effect air flow unless it broke off its hinge, it simply routes air from blower either thru the heater core(HOT) or around the heater core(COLD) or anywhere in between

 

Thank you for the reply. I will check the vacuum lines when I can. It just seems very odd that letting the truck cool down for a number of hours solved the problem. It was working as expected for an hour or more before failing again. If it was a vacuum leak I would have expected that cooling down would not have solved the issue but could be. I believe that when there is a loss of vacuum from the reservoir it directs all air flow to the defrost vent as a safety default. I doubt that a varmint nest or debris would result in an intermittent problem but I've been wrong many times before so I will try and see what I can find out next chance I get.
Thanks again for your help.

 

Yes, listed is just the most common failings
Could be one of the vacuum "motors" is not working well, or door is sticking
Diagram here: https://www.ford-trucks.com/forums/a...ntid=517&stc=1
NV = no vacuum
PV = partial vacuum
V = full vacuum

Re-circulation door is only used in MAX AC and if its intake port in passenger side foot well was partially blocked then air flow would be limited when MAX AC was selected


Could be the blower cage is slipping on shaft, so sounds like its running at high but flow is low

 

Sounds like the evaporator is icing up, that could be low refrigerant.

 

+1 ^^^^

Never thought of that

Even fits the symptoms better, had better air flow after sitting and ice melted

 

I will definitely check that out as well. It does seem more likely based on how this is happening. There is likely a slow leak in the refrigerant lines somewhere that is the cause of the original issue with blowing only warm air when the AC was on. Will have to pressure test the system.

 

Just to update you. It was the refrigerant that was low and causing excessive ice buildup.
Thanks for the help!