My AC is back in business! I spent a total of $22 to fix it!

I have a 2003 F150 5.4L that would only blow thru the defrost vent when in MAX AC mode. Here's the outline to my problem and the fix below.

1. When set to MAX A/C the air would only blow thru the defrost vent when at idle or driving down the road.
2. I purchased a vacuum gauge with pump and thoroughly tested all the vacuum lines starting from the intake manifold back. All vacuum lines and the vacuum canister behind the battery would hold a vacuum.
3. I then hooked up the vacuum gauge w/pump to the vacuum line going to the AC system at the firewall (on the passenger side of the firewall).
4. I could pull a vacuum in all modes when running except for MAX AC.
5. After reading this thread I came to the conclusion that the solenoid responsible for MAX AC had a bad o-ring in the AC dash control unit (EATC Module).
6. I removed the following to get the AC control unit out:
6a. Remove cup holder in dash
6b. With the cup holder removed, put your fingers up in the dash and press against the radio dash trim to create a gap between where you can get a grip and pull the trim piece off. The trim piece just pulls backward from dash, I just used my hands, no tools.
6c. At this point, I had to remove my radio to get to the back of AC control unit to disconnect it. So I bought the U-shaped radio removal tools for Fords and removed my radio.
6d. With the radio disconnected, I remove the 4 T20 torx screws holding the unit in the dash. Then I removed two 10mm nuts on the back of the unit that hold on the molded vacuum line assembly. Then I removed the two plugs connected to the unit.
7. With the AC control unit disconnected, I disassembled the control unit as outlined in this thread and replaced all 4 o-rings. I made sure to put a good coating a pure silicone grease on the o-rings.
8. With the unit reassembled, I loosely connected it back in the truck and tested the MAX AC. It worked!
9. I reinstalled the AC control unit, radio, radio dash trim and cup holder.
10. Done!

Expenses:
$12 - O-Rings - I had to buy 4 packs of 16 assorted o-rings to get 4: 5/32" ID x 9/32" OD x 1/16" o-rings - AutoZone
$7 - Radio removal tool - AutoZone
$3 - Silicone Grease - HomeDepot (Plumbing section)

Time:
I work fairly slow and methodical so it took me about 4 hours. I could do it again in less than 1 hour. It's not that difficult of a project.

 

Many have posted on this thread stating that if anyone needs any orings to simply send a request. Well, some of those folks haven't posted for over a year or two. So, I need two sets of orings to do two vehicles. If any of you folks would be so kind to text me at 615-476-91zerozero, I'll text you my address. Thanks, Frank.

 

Need orings. Two sets please. Text me please at 615-476-91zerozero for address.

Thanks,

Frank

 

O-rings sent. The images in post #11 of this thread have been restored for those of you that are performing this procedure. They were temporarily removed from their hosting site.

 

I appreciate this posting as my son and I just completed this fix to his 2003 F-150 SuperCrew. The problem I had was trying to find the correct O-rings. Finally was able to order them from W.W. Grainger. I had to buy 100 of them for $ 9.96. Money well spent in my opinion.

Here's the W.W. Grainger Item # and description info (Translated from McMaster-Carr product):

Grainger Item Number: 1REC2
Description: O-Ring,Silicone, AS568A-007, PK 100
Fractional Width: 1/16"
Color: Red
Inside Diameter: 5/32"
Outside Diameter: 9/32"

 

Thanks to Marauder2004 for the o-rings. I now have cold ac blowing on me from the vents. Took me about an hour and a half. I could do it now in less than an hour. Here's a very helpfil video on this from Youtube:

http://m.youtube.com/watch?v=

Couple of notes. On the 1997-2003 F-150s, the easy way to get to your EATC is to simply pop off the trim that surrounds your radio, eatc. The one with the vents in it. It just pulls right off. 4 screws and the eatc is out. Really simple. I saved myself over 900.00 from the dealer. Cost me an hour and a half of my time.

The original black orings on mine were thin and very hard. I broke three taking them off. I used silicone spray on the new ones. You can simply plug the eatc in when done and test.

Once all the little screws are removed from the body and you are finished with replacing the orings, you'll need to use care when bending all the little tabs but don't be afraid to gently tap them back down when reassembling. The larger tabs on each end can be bent back into place with your fingers. The smaller tabs will take pliers or a small hammer tapping gently on them.

Be careful when removing each cylinder from the main body. There are small springs along with little inserts at the end of the springs. These can fall out. Make sure you pay attention to orientation as you disassemble.

The youtube video is very helpful, quick and easy. The actual instructions are in the second half of the video.

Man, I love the internet.

Thanks again to everyone who helped here.

 

I couldnt pull up the video whats the url again/

 

Youtube video link:

 

THANK YOU SO MUCH!!! the exact same thing was happening to my 03 KR. Only the defrost and vent settings worked, everything else just blew through the defrost.

I registered just to thank Marauder2004. His post, and the pics/tutorial as well.

I fixed my 2003 F150 5.4 King Ranch using this method. Total spent, Redbull + O-Rings = 5 dollars WELL spent.

The only hiccup I had was when I removed the tube inside the solenoid frame. It's the tube with the factory O-Ring. I was unsure of how to remove the O-Ring, I thought the bottom part of the tube slid off, so I tried to pull it out so I could remove the O-Ring but that didn't work. Then I realized maybe I just need to remove the O-Ring with a flathead, and as I tried the old O-Ring broke off. It must've been really old/hard because it broke off in pieces.

I then put #008 O-Rings onto the rings. (which I bought at Grainger). It fit well, and then as I tried to put it back into the solenoid frame (where the tube is with the spring and bottom metal piece) the tube that has the O-Ring wouldn't go in easily. I used some pliers to grab the end of the tube and slowly pushed it in. That worked well.

After assembling back the EATC unit, I put it back onto the King Ranch, and voila. Everything worked great, from the MAX AC, to the Floor settings, everything.

Thank you so much again!!!

 

Yes! That was it. Worked like a champ. Not too complicated. Self thread nuts were a little difficult to get to, but got it done.

 

Got the o-rings at the Ford house. 50 cents. Hardware store o-rings were too fat.

 

Thank you Marauder2004 and others who have had the EATC problem. I searched all over for vacuum leaks and could not find any. I found this thread, followed the instructions, and now I'm ready for triple digits in AZ with my ICE COLD ac blowing in my face again! $3.76 for o-rings and silicone grease and some deteriorated tubing. Took me about an hour. Thanks to all who have shared your experiences on this problem I read every one of them and decided to join! Cannot say thank you enough!

 

Thanks, was looking for help with this King Ranch.. think I found the right site. oath-Honor

 

So I have replaced every vacuum line on my truck plus check valve's and vacuum reservoir's to fix Max a/c air/defroster problem, thats including the 4x4. I have 2 questions first... the easy one where does this large hose go? read it was a vent for the transfer case but not sure.? hmmm... well i cant post the pic but its the large hose along with the 2 vacuum lines going to the transfer case from valves. It has a broken fitting thats still in it and just hangin out and looks like a quarter inch line. second I have 21 inch hg vacuum at the EATC but full vent port coming out is 8 - 10 inches so I am losing 12 inch hg through the unit. When I push floor and test that portI am showin 20 inches Hg. (yes I plugged all open ports when testing) pretty sure I need to replace the o rings in the EATC Head unit correct? Thanks!!

 

I used 008 size o rings and everything works fine. thanks for the info!!