A/C Question
Thread Starter
|
Senior User
Joined: Jan 2010
Posts: 269
Likes: 2
A/C Question
Sitting in stopped traffic for about 45 minutes and AC slowly starts blowing warmer air. Temp about 95 and very humid. Felt like AC just freezing up, but no frost on anything when I looked under hood. Hoping freon problem. Any suggestions on diagonosing the problem ? About to start looking at it this morning. Thanks in advance.
Jed
Jed
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,353
Likes: 5,946
From: Lake Hartwell, GA
Might be this...
https://www.ford-trucks.com/forums/1...stem-seal.html
Better chance it is this...
It could be a number of other things as well, including the freon level.
https://www.ford-trucks.com/forums/1...stem-seal.html
Better chance it is this...
It could be a number of other things as well, including the freon level.
Fleet Mechanic
Joined: Jul 2003
Posts: 1,614
Likes: 22
From: Springfield, PA
Can't help you, but I have the same issue with the wife's '05 Equinox for two years now. I checked the system pressure and was certain that it was correctly filled, but one really hot week when I was away she took it to a shop where they "refilled" it, but no change. They added dye and nothing leaks, and it works at speed. I've been wondering whether it's the a/c clutch simply slipping at low engine speeds (idle), but I would've expected it to fail completely by now.
FTE-Spread The Knowledge
Joined: Feb 2008
Posts: 2,287
Likes: 243
Remove the washer on the AC compressor clutch. Works GREAT, and takes a couple of minutes to complete.
https://www.ford-trucks.com/forums/a...7&d=1495050618
https://www.ford-trucks.com/forums/a...7&d=1495050618
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,353
Likes: 5,946
From: Lake Hartwell, GA
Something else just came to mind, but might not apply to the 7.3. We have a Subaru that the relay for the a/c system would intermittently fail on. I replaced the relay on a guess and it has been good since.
The compressor for the Subaru would kick on and off at highway speeds and slows speeds as it is designed to do. Although, 50% of the time the compressor would have a problem kicking back on and would try over and over again. I took it to a shop that I trusted to have the freon checked and they filled it exactly to specifications. The A/C seemed to be better for a bit, but went right back to causing problems again. I figured I would spend $5 on a relay before taking it back to the mechanic to try another fix and the A/C has been perfect since.
Keep in mind, I am in GA and we have had rain non-stop here for weeks so the A/C is a must...
The compressor for the Subaru would kick on and off at highway speeds and slows speeds as it is designed to do. Although, 50% of the time the compressor would have a problem kicking back on and would try over and over again. I took it to a shop that I trusted to have the freon checked and they filled it exactly to specifications. The A/C seemed to be better for a bit, but went right back to causing problems again. I figured I would spend $5 on a relay before taking it back to the mechanic to try another fix and the A/C has been perfect since.
Keep in mind, I am in GA and we have had rain non-stop here for weeks so the A/C is a must...
More Turbo
Joined: Jun 2017
Posts: 731
Likes: 15
From: Arizona
I had my system recharged but it would still quit working as the temperatures began to climb.
When I checked the system with a gauge while it was still hot, I found it was overcharged for the ambient temperature.
Apparently they had recharged it with an 80 degree setting and when the outside temps got over 95 it would reach into the red zone and trigger the shut off switch to protect the system.
I set the gauge to the correct outside temperature and ended up removing some of the refrigerant to get it to read in the safe zone. The compressor clutch immediately kicked in the AC started working fine.
When I checked the system with a gauge while it was still hot, I found it was overcharged for the ambient temperature.
Apparently they had recharged it with an 80 degree setting and when the outside temps got over 95 it would reach into the red zone and trigger the shut off switch to protect the system.
I set the gauge to the correct outside temperature and ended up removing some of the refrigerant to get it to read in the safe zone. The compressor clutch immediately kicked in the AC started working fine.
Tuned
Joined: Mar 2016
Posts: 354
Likes: 0
A/C system will blow warmer air when you are not moving. There is not much air flowing through the condenser when stopped so the refrigerant isn't able to do it's job as well. Newer vehicles with electric fans or electric clutch driven fans can reduce this symptom by driving the fan while the A/C is on regardless of engine temp. The 7.3 fan is a mechanical clutch that relies on the temp around the fan so if the engine isn't hot enough the fan isn't fully engaged.
Trending Topics
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,353
Likes: 5,946
From: Lake Hartwell, GA
A/C system will blow warmer air when you are not moving. There is not much air flowing through the condenser when stopped so the refrigerant isn't able to do it's job as well. Newer vehicles with electric fans or electric clutch driven fans can reduce this symptom by driving the fan while the A/C is on regardless of engine temp. The 7.3 fan is a mechanical clutch that relies on the temp around the fan so if the engine isn't hot enough the fan isn't fully engaged.
The A/C system is pretty complex for the amateur or shade tree mechanic in my opinion. The two most common problems with the 7.3 A/C is freon and the shims on the clutch.
The evaporator coil cleaning procedure I linked is a good thing to do, but not normally the root of the problem.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
Tuned
Joined: Mar 2016
Posts: 354
Likes: 0
I didnt see where the temp was measured at ambient air temp. As the engine bay heats up as you are sitting the condenser/refrigerant get a warmer and the problem compounds. Does the A/C system function normal when moving?
Lead Driver
Joined: Sep 2010
Posts: 7,793
Likes: 50
Can't help you, but I have the same issue with the wife's '05 Equinox for two years now. I checked the system pressure and was certain that it was correctly filled, but one really hot week when I was away she took it to a shop where they "refilled" it, but no change. They added dye and nothing leaks, and it works at speed. I've been wondering whether it's the a/c clutch simply slipping at low engine speeds (idle), but I would've expected it to fail completely by now.
Thread Starter
|
Senior User
Joined: Jan 2010
Posts: 269
Likes: 2
You guys are great!!!! Got plenty ideas now before taking it somewhere... Made it beach and was depressed about riding home in 100 degree Wx until reading all the ideas. One other question. Will low coolient level cause this ?
Fleet Mechanic
Joined: Jul 2003
Posts: 1,614
Likes: 22
From: Springfield, PA
I suppose a low coolant level can cause it if that raises your engine temp, as that will raise the radiator temp behind the a/c condenser.
OMG yes!! And the Chevy forum blows too. I'm spoiled by all you guys here! I've been chasing brake/ front hub squeals for four years now. Replaced EVERYTHING up front, still squeals just rolling down the road. We now have an 18 month old grandson, and it's to the point where she's afraid to drive him in her car. The only good thing was she got bumped from behind last year (no injuiries) but we got someone else's insurance to repaint the front and rear so it looks great. Likely trade for something soon.
ain't they the biggest POS vehicles made! My ex has same year. Replaced everything within b the 1yr dating her. Made me feel like a tramp, since that's all I did, was week on it....radiator, suspension, water pump, tstat, alternator, mounts(that was fun)... Ended up, having to remove entire dash/console assy to repair the accumulator door since the heatr stopped working... Whatta nightmare
Thread Starter
|
Senior User
Joined: Jan 2010
Posts: 269
Likes: 2
A/C system will blow warmer air when you are not moving. There is not much air flowing through the condenser when stopped so the refrigerant isn't able to do it's job as well. Newer vehicles with electric fans or electric clutch driven fans can reduce this symptom by driving the fan while the A/C is on regardless of engine temp. The 7.3 fan is a mechanical clutch that relies on the temp around the fan so if the engine isn't hot enough the fan isn't fully engaged.
Thread
Thread Starter
Forum
Replies
Last Post
jwhopson
1999 - 2003 7.3L Power Stroke Diesel
7
Aug 20, 2015 05:57 PM
VA250SD
Cooling, Heating, Ventilation & A/C
3
May 12, 2012 11:58 AM