AC cooling temp?
Elder User
Joined: Dec 2009
Posts: 864
Likes: 0
From: Fort Campbell, KY
only problem is your evaporator will freeze in short order. Where you live the humidity may be low enough, but down here in the south, that temp would turn my evaporator into a 4" block of ice in less than five minutes. 
Lead Driver
Joined: Dec 2003
Posts: 5,250
Likes: 42
what was the outside temperature when that picture was taken??
Hotshot
Joined: Jan 2010
Posts: 10,060
Likes: 491
From: Bristol, TN.
I expect to see temperature difference in a working AC system after about 15 minutes of 18-25 degree between outlet and return air temperatures. Exact temperature is affected by outside ambient and humidity.
There is a little wiggle room here of a few degrees. I ran the same test in the picture using my Fluke meter in the same position on both my F150 and my F350 Powerstroke and got about 54 degrees at start-up dropping to about 42 - 44 degrees after an hour's run time. My temperature differences inlet to outlet were between 25 and 27 degrees on this dry high 80s day.
That's the pattern I see pretty much daily in my work.
Steve
There is a little wiggle room here of a few degrees. I ran the same test in the picture using my Fluke meter in the same position on both my F150 and my F350 Powerstroke and got about 54 degrees at start-up dropping to about 42 - 44 degrees after an hour's run time. My temperature differences inlet to outlet were between 25 and 27 degrees on this dry high 80s day.
That's the pattern I see pretty much daily in my work.
Steve
Thread Starter
|
Junior User
Joined: Apr 2011
Posts: 52
Likes: 0
From: Chandler
I went and bought some gauges, called a couple local AC shops and they said with our current temperatures the low side should be 45-5psi5 and the high side should be near 215psi plus or minus but in the green.
Put on the gauges and I was up near 65 and the high was up near 315, so I brought it down to 55 and the high side hit 215.
I picked up all of the parts and the #74857 from Autozone, I was getting some bulbs and when I asked for the item the guy said 'This isn't for your truck' and the guy was reluctant to get it for me. I told him 'Trust me, I have instructions from the Internet.' I'll have to put it on once we're on vacation, no time before then which makes me sad because we'll be driving in 110 heat. Really really really appreciate the info and help.
Does it matter what line you put the control valve on? water in or water out?
Put on the gauges and I was up near 65 and the high was up near 315, so I brought it down to 55 and the high side hit 215.
I picked up all of the parts and the #74857 from Autozone, I was getting some bulbs and when I asked for the item the guy said 'This isn't for your truck' and the guy was reluctant to get it for me. I told him 'Trust me, I have instructions from the Internet.' I'll have to put it on once we're on vacation, no time before then which makes me sad because we'll be driving in 110 heat. Really really really appreciate the info and help.
Does it matter what line you put the control valve on? water in or water out?
Posting Guru
Joined: Feb 2010
Posts: 1,411
Likes: 1
From: Opelika, AL
i have the same exact temp gun and took readings at the same spot yesterday with the fan on high max cool and was getting -10f with outside temp in the 90's. today i took the readings and got 0f.
my condensor was replaced last year not sure what pressure its charged to? i also adjusted the air gap on the clutch and also took the blower motor out to clean the coils.
does that sound right? i have never had a freeze up problem
my condensor was replaced last year not sure what pressure its charged to? i also adjusted the air gap on the clutch and also took the blower motor out to clean the coils.
does that sound right? i have never had a freeze up problem
Hotshot
Joined: Jan 2010
Posts: 10,060
Likes: 491
From: Bristol, TN.
i have the same exact temp gun and took readings at the same spot yesterday with the fan on high max cool and was getting -10f with outside temp in the 90's. today i took the readings and got 0f.
my condensor was replaced last year not sure what pressure its charged to? i also adjusted the air gap on the clutch and also took the blower motor out to clean the coils.
does that sound right? i have never had a freeze up problem
my condensor was replaced last year not sure what pressure its charged to? i also adjusted the air gap on the clutch and also took the blower motor out to clean the coils.
does that sound right? i have never had a freeze up problem
Steve
Laughing Gas
Joined: Feb 2004
Posts: 1,080
Likes: 1
From: Elsinboro, NJ
It was about 80-85 degrees out that morning and Humid with a capital H.
Although I should note that the temp gun used was a christmas gift and I don't know where it came from, but I can tell you I have to turn off the air alot because I'm too cold at times.
Although I should note that the temp gun used was a christmas gift and I don't know where it came from, but I can tell you I have to turn off the air alot because I'm too cold at times.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Cargo Master
Joined: Apr 2007
Posts: 2,333
Likes: 1
From: St. Louis, Mo.
Are these temps at idle? - The faster you go the more efficient the a/c system will be, outlet temps will get colder as the pressure in the system drops as more air is moved across the condenser. Run down the highway & see what your outlet temps are at 60 mph.
Posting Guru
Joined: Jan 2007
Posts: 2,364
Likes: 3
From: Gilbert Az.
I went and bought some gauges, called a couple local AC shops and they said with our current temperatures the low side should be 45-5psi5 and the high side should be near 215psi plus or minus but in the green.
Put on the gauges and I was up near 65 and the high was up near 315, so I brought it down to 55 and the high side hit 215.
I picked up all of the parts and the #74857 from Autozone, I was getting some bulbs and when I asked for the item the guy said 'This isn't for your truck' and the guy was reluctant to get it for me. I told him 'Trust me, I have instructions from the Internet.' I'll have to put it on once we're on vacation, no time before then which makes me sad because we'll be driving in 110 heat. Really really really appreciate the info and help.
Does it matter what line you put the control valve on? water in or water out?
Put on the gauges and I was up near 65 and the high was up near 315, so I brought it down to 55 and the high side hit 215.
I picked up all of the parts and the #74857 from Autozone, I was getting some bulbs and when I asked for the item the guy said 'This isn't for your truck' and the guy was reluctant to get it for me. I told him 'Trust me, I have instructions from the Internet.' I'll have to put it on once we're on vacation, no time before then which makes me sad because we'll be driving in 110 heat. Really really really appreciate the info and help.
Does it matter what line you put the control valve on? water in or water out?
Posting Guru
Joined: Feb 2010
Posts: 1,411
Likes: 1
From: Opelika, AL
I am certainly not disputing your findings, but it is really strange. My trucks are cooling fine and my Fluke gives me reading nothing like these and I think I am taking my temps the same way. I would expect your truck to feel like a refrigerator with so low a supply side temperature. We both have high end equipment. What gives? In everything I work on a freeze control kicks the compressor off line when the coil gets to about 38 degrees. Anyone have any ideas?
Steve
Steve
Lead Driver
Joined: Dec 2003
Posts: 5,250
Likes: 42
f**d specs claim between 45-55 vent temp on our trucks (of course it will vary with ambient temps).
have seen the snap-on thermometer in the vent hit ~35 a time or two, but other than that, 100* outside and it will range from 40-58 depending on fan speed and if it is highway or stuck in traffic.
funny thing is, the temp will always read lower with the fan at the lowest setting.
Posting Guru
Joined: Feb 2010
Posts: 1,411
Likes: 1
From: Opelika, AL
there is NO way those temps are accurate. thought maybe it was 0 outside and that pic was posted for a laugh, lol....
f**d specs claim between 45-55 vent temp on our trucks (of course it will vary with ambient temps).
have seen the snap-on thermometer in the vent hit ~35 a time or two, but other than that, 100* outside and it will range from 40-58 depending on fan speed and if it is highway or stuck in traffic.
funny thing is, the temp will always read lower with the fan at the lowest setting.
f**d specs claim between 45-55 vent temp on our trucks (of course it will vary with ambient temps).
have seen the snap-on thermometer in the vent hit ~35 a time or two, but other than that, 100* outside and it will range from 40-58 depending on fan speed and if it is highway or stuck in traffic.
funny thing is, the temp will always read lower with the fan at the lowest setting.
yeah i didnt think it was right....the gun must be way off when its been sitting in 120*f truck. i have it in my office with me now and its reading normal temps again....ill see what it says on the way home and let yall no. last summer i had the instant read thermometer stuck in the vent and was seeing about 45 like you said.