A/C problems
Thread Starter
|
Senior User
Joined: Feb 2003
Posts: 206
Likes: 0
A/C problems
Two days ago my A/C was working fine & then suddenly started blowing warm air. I thought maybe I had a leak somewhere & had lost my freon. I pulled the cap off the valve on the line going to the condensor & pushed it in just long enough to confirm pressure. There is at least some pressure on the line, but I don't know how much as I don't have a gauge. It didn't work for two days. The compressor would constantly cycle on & off. Then tonight it started working again & cooled as good as ever, but the compressor still cycled more than usual. Any ideas on what could cause this? Could it be the low pressure switch causing the compressor to cycle excessively? If I was low on freon, it seems like it may not work AS WELL at some times & then seem to work fine at others, but it actually felt like I had the heat on. Thanks in advance for any input. MS is no fun without A/C.
New User
Joined: May 2003
Posts: 7
Likes: 0
From: E. WASHINGTON
A/C problems
Its just a little low. The pump will come on around 65psi and shut off at about 25psi. (this is on the low side) So what is happening is the pump comes on, and pumps the coolant to the high side, lowering the low side. with not enough coolant the low side is dropping below the min. Therefor shutting off. As soon as the high side evens out with the low side, and the low side reaches 65psi the pump is comming back on.. Bottom line... Just need some more juice. If you system is a r134 system then you can go to any autoparts store and pick up a kit to add some more coolant, or take it to most lube shops. IF it is R-12 then have it converted to r134...
Just my 2cc's
Mike.
Just my 2cc's
Mike.
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
A/C problems
1993F150XL
Look on the sticker on your core support - is your system R-12 or R-134a? You can buy a cheap (but effective) gauge at Wal-Mart for 134; maybe under $10.
mpippins
Your numbers are right for 134, but R-12 switches are set around 19 off - 35 on.
Look on the sticker on your core support - is your system R-12 or R-134a? You can buy a cheap (but effective) gauge at Wal-Mart for 134; maybe under $10.
mpippins
Your numbers are right for 134, but R-12 switches are set around 19 off - 35 on.
Freshman User
Joined: Jul 2002
Posts: 44
Likes: 0
From: Memphis USA
A/C problems
Yes, it sounds like it's low; the failure mode for limit switches is usually always-open or always-closed..
But, if it is low, you should probably try to find the leak. Unless this is the first time it's caused trouble in 10 years, loss of charge isn't too great a concern.
FYI: a system that's losing charge but which still seems to be operating properly will start to "grow frost" on the line to the evaporator.. You'll be more likely to see it if you run the system on MAX and the fan on low with the engine at 1500 RPM for a couple minutes. It's an easy check...
Don't just put the R134a service fittings adapters on an R12 system and add R134. Be careful about adding off-the-shelf one-can-fixes-alll (refrigerant/leak stopper/dye/oil) to your Ford system; the lubricant is usually too viscous for Fords.
But, if it is low, you should probably try to find the leak. Unless this is the first time it's caused trouble in 10 years, loss of charge isn't too great a concern.
FYI: a system that's losing charge but which still seems to be operating properly will start to "grow frost" on the line to the evaporator.. You'll be more likely to see it if you run the system on MAX and the fan on low with the engine at 1500 RPM for a couple minutes. It's an easy check...
Don't just put the R134a service fittings adapters on an R12 system and add R134. Be careful about adding off-the-shelf one-can-fixes-alll (refrigerant/leak stopper/dye/oil) to your Ford system; the lubricant is usually too viscous for Fords.
Thread Starter
|
Senior User
Joined: Feb 2003
Posts: 206
Likes: 0
A/C problems
Thanks for all the input, guys. My system is still R-12, but I can probably borrow a gauge from someone to confirm that it is low. I am almost certain that's my problem, as the line to my evaporator is frosting. I have only owned this truck for just over two years, but this is the first problem I've had. Could this just be a slow leak or should I be concerned about finding it? It just seems to me that if the leak was very bad, I would lose all of my freon. By the way, I still have a few cans of R-12 that I've had for years. Are there any disadvantages of staying with R-12, being as I already have it? I know the usual reason for converting to R-134 is cost, but since I have the R-12, it seems senseless to let it go to waste. Any opinions? Thanks again for the help.
Posting Guru
Joined: Oct 2000
Posts: 1,577
Likes: 0
From: Southern MD
A/C problems
Stay with the R-12 as long as you can. I'm getting ready to reseal my '89 Mustang, and I'm staying with R-12.
Trending Topics
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
A/C problems
Originally posted by 1993F150XL
it seems senseless to let it go to waste.
it seems senseless to let it go to waste.
Find the leak first, THEN decide whether to top it off or fix it.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread Starter
|
Senior User
Joined: Feb 2003
Posts: 206
Likes: 0
A/C problems
You're right, Steve. I guess the leak must be pretty bad since it quit working all of a sudden. Is a "sniffer" (I don't know the correct terminology) the only way to detect a leak, or is there a method I'm not aware of?
Mountain Pass
Joined: Feb 2003
Posts: 136
Likes: 3
A/C problems
I just recently had to replace the pressure switch out on my 92. It could be bad also. It did the same as yours did, just stopped working one day. But once you get it all checkeed out then youll know for sure.
Freshman User
Joined: Jul 2002
Posts: 44
Likes: 0
From: Memphis USA
A/C problems
This is always the questions when dealing with a system that isn't regularly monitored: "How bad is the leak?" It's the same thing with oil leaks, coolant leaks, etc. All of a sudden, something happens.
It's pretty obvious that you're running low; I'm pretty sure a gauge will tell you that. Buut, did you notice a change in cycle time in the months leading up to "suddenly quit working?" that's one clue.
Yes, stay with the R12 if you can, if for no reason other than iyou can avoid the hassle of an evacuation. I've converted some to R134a: a through flush is absolutely necessary, maybe a drier replacement. On an old R12 system that experienced the Black Death I've loaded up with R414a. R414a isn't approved tfor MVAC systems, but we're scratching our heads asking, "Why not?" A firend and I have converted a couple R12 systems and are keeping an eye on 'em.
It's pretty obvious that you're running low; I'm pretty sure a gauge will tell you that. Buut, did you notice a change in cycle time in the months leading up to "suddenly quit working?" that's one clue.
Yes, stay with the R12 if you can, if for no reason other than iyou can avoid the hassle of an evacuation. I've converted some to R134a: a through flush is absolutely necessary, maybe a drier replacement. On an old R12 system that experienced the Black Death I've loaded up with R414a. R414a isn't approved tfor MVAC systems, but we're scratching our heads asking, "Why not?" A firend and I have converted a couple R12 systems and are keeping an eye on 'em.
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
A/C problems
R-414A (51% R12, 28.5% R124, 16.5% R142b, 4% R600a) has been SNAP-listed for MVAC use since at least '98. It requires dessicant XH-9, a label with a red background, white foreground, a .305" diameter hi service port with 32 RH threads per inch, and a .368" lo port with 26Rtpi. The 30lb containers use the same fitting as the hi side, and the small cans use 14mmx1.25 LH threads. It's supplied by People's Welding 800-382-9006.
Last edited by steve83; Jun 15, 2003 at 11:05 PM.
Freshman User
Joined: Jul 2002
Posts: 44
Likes: 0
From: Memphis USA
A/C problems
Steve83,
Since '98? Hmmm... That;s not what I thought. Yes, I know that it's a mixture -- but I don't remember seeing R12 on there. I'll have to check out the label again. Thanks!
Where did you find this information?
Since '98? Hmmm... That;s not what I thought. Yes, I know that it's a mixture -- but I don't remember seeing R12 on there. I'll have to check out the label again. Thanks!
Where did you find this information?