Air Conditioner -- General Info

[paholskila]

The A/C on my 2002 Ranger (2.3 engine) still blows very cold after 130k miles, to my surprise and pleasure -- never had to do anything to it. But I noticed it takes longer to get really cold, maybe as much as 10 minutes. So I bought a recharge kit. Noticed when compressor clutch was NOT engaged, low-side pressure was around 120; when the compressor kicked in, even before recharge the pressure was in the good range, something like 30-35 as I recall. Went ahead and squirted in the freon, expecting to see that pressure rise somewhat, but it never did, even when the can was completely empty. Took it for a drive, still blows nice and cold, but still takes up to 10 minutes to get to that point. So apparently the recharge did pretty much nothing for me except lighten my wallet by $30 or so. I can live with the A/C the way it is, but am curious why the long time to get really cold, if the freon is solidly in the good range. Can anybody who has a good handle on auto air conditioners shed any light for me? Is there some other component of the system that may be failing and needs to be watched?

[cvar]

See http://visualbits.net/Ford%20Ranger%...-2008/HVAC.pdf

[paholskila]

Tons of detailed info there, makes my head hurt to read it all, but I'm hoping there's a short simple answer to my central question: If my 2002 Ranger A/C was blowing cold within 2-3 minutes when new, and it now takes 10 minutes, and the low-side pressure reads good, and I just shot a whole can of freon into the system with no change in the pressure reading, what's the most likely reason for the slow initial cooling response? And is it anything I can do anything about, inept mechanic that I am, or should I anticipate a big A/C bill in my future? (One thing reading that manual definitely convinced me of is that any major work on the A/C system is way beyond me.)

[ramblinman]

Same exact thing is happening to me. Hence why I just joined the forum lol. I've owned this truck for 6 years and it would blow cold the moment I fired it up and now this summer all of a sudden it blows hot for about the first 10 minutes and then it will get ice cold again. The guy at the Advanced Auto Parts store told me "thats just happens". BS. Obviously something went wrong considering its just came out of nowhere.

[paholskila]

Agree. Just simple "I can almost change a faucet washer" logic tells me that something in the A/C system that's supposed to compress the freon, or something, isn't working as well as it did when new. But it does seem to hold pressure, and does eventually get cold, so I was hoping somebody who knows a LOT about auto A/C would say something like "Oh, that's probably worn O-rings in your accumulator, not something an amateur can replace," or something equally informative for near-dummies like me. Was out running around yesterday, and AFTER the 10 minutes I had to tweak the temperature setting as it was actually TOO cold.

[cvar]

If it does get really cold (eventually) then the refrigerant levels & compressor must be working ok. That means it's most likely an electrical issue.

Check your A/C compressor clutch relay which may be going bad (inside your engine bay's Power Distrib Box). Swap it with another matching one. Also check for 12V power at the A/C compressor pins, and also at the A/C ON/OFF switch on the accumulator.

The other possibility is lack of vacuum. A vacuum leak (plain air, not refrigerant) affects any heater controls that are vacuum operated, such as plenum door flaps, recirc. switch, etc., not the A/C itself.

Aside:
Some Advanced Auto salesmen don't know squat. Only what their part computers tells them. Two wks ago, they read my ODB2 codes and then told me that my p0171/p0174 was very rare (ie, they never heard of it) & was definitely vehicle-specific to just our car alone. Yeah, right. Sure.

P.S. Try reading that document. You'll learn stuff. Otherwise you're gonna forever remain just as clueless as the AA salesmen you derided.

[paholskila]

Originally Posted by cvar

P.S. Try reading that document. You'll learn stuff. Otherwise you're gonna forever remain just as clueless as the AA salesmen you derided.

Mistaken identity -- I haven't been to Advanced Auto, don't even think there is one in our town. But I will observe that in my experience, if one makes the rounds of auto parts stores and asks the same question, sooner or later he's likely to get completely different, if not conflicting, answers.

[CJGill]

My 2011 Ranger started blowing tepid air on any air conditioner setting. It never really gets cold like when it was new.
Took it to one of the quick oil change places and they tested and said it had good compression and they could charge it for me for about $140.
Decided to take it to a dealer to have it checked. Was told the compressor is bad and they gave me an estimate of over $900 for replacement. This, to me is outrageous. The vehicle only has 22,000 miles on it and is just out of warranty, of course.
Is this a normal cost for repair? (I plan to shop around)
At least I can drive it with the windows open.

[paholskila]

Well, I paid about $35 for a recharge kit at AutoZone, and it was a very simple process, although in my case it didn't make any difference. I'd certainly consider trying that if I were in your shoes, before paying the kind of prices you were quoted.

[04by4]

Know this is an old thread but wondering if anything ever came of your "central issue." Also by what you said it is curious that your compressor was cutting off and on and not continuously running when you were measuring pressure and refilling Refrigerant. If that is what you meant that certainly signifies an issue and would make sense that it is taking that long to charge. To the guy that posted last about his compressor I'm not an expert but 900 sounds pricy my buddy got quoted 700 from Firestone. Will update outcome of that if he ever commits to it. I've been doing some work and figuring out on some AC basics and have seen positive results so I'd like to explore this issue further. Have some tips if you're still around on fourm to the original creator of of this thread or anyone else.

[97rangerstepside]

I've been having a problem for awhile now with my ac where the compressor clutch kicks iin and out even when its got a full charge, driving down the highway sometimes the ac will totally quit blowing cold air, is this an issue with the compressor clutch? Or is it a connection issue somewhere?

[cvar]

Could be the Wide-Open-Throttle relay intentionally cuts off power to the A/C compressor, to give you more engine power at WOT. See lower right corner of this 1997 A/C wiring schematic:
http://i.imgur.com/7bJyuXd.png

[04by4]

..

[cvar]

Please start your own thread? Don't hijack this one!

Originally Posted by 04by4

In idle is your clutch consistently staying engaged?

Nope. Mine cycles ON & Off, a few times each minute, depending on outside temperature (independent of engine speed). Just like Ford says it should, per charts near top of this:

[04by4]

Did not mean to invade on your thread? Cool info.