Desperatly seeking A/C help...

[areonic1]

Alright, did what you asked.....

With the car totally off, it reads well beyond 150, my gauge maxes out at 150
Now, start the car, and the at idle, with the AC running, it sits between 43-45, slowly varies
Soon as we sat on it, at 1500rpms, the pressure dropped, to at least under 35, cause as the gauge dropped to 35 it would kick ac off, the gauge would up to around 120ish like the ac wasnt on

 

[areonic1]

Also the AC cycling was a few sec off and a few sec on

 

[Iron Weasel]

Alright, did what you asked.....

With the car totally off, it reads well beyond 150, my gauge maxes out at 150
Now, start the car, and the at idle, with the AC running, it sits between 43-45, slowly varies
Soon as we sat on it, at 1500rpms, the pressure dropped, to at least under 35, cause as the gauge dropped to 35 it would kick ac off, the gauge would up to around 120ish like the ac wasnt on

So you're still at about the same pressure as you were earlier then....that's good. When you revved it and the pressure dropped to 35psi, did the compressor shut off?

Lastly, how long would you estimate the compressor clutch is engaged and disengaged? Like, does it stay on for 3 seconds, off for 10 seconds, on for another 3, and so on?

 

[kelvin37]

i think you said that your had a new compressor, did that come with a clutch? mine did. with the compressor running you should be between 48 and 58 psi. that would be why your compressor cycles under a load. when you are first adding a charge are you vaccuming in down first? if you still have issues then i can give you my phone and walk you through it.

 

[areonic1]

Yea the compressor shut off when it went below 35, and as an estimate, it was shutting off for like 3 secs, on 3 secs, off 3 secs, on 3 secs


KELVIN
It did come with a clutch

 

[Iron Weasel]

As Kelvin pointed out, you're probably low on refrigerant at the moment.
Pressure @ 1500RPM should be 45psi - 50psi per the chart on the first page.

If it still acts up after having the proper amount of refrigerant, my educated guess is the A/C Clutch Cycling Switch located on the accumulator.

Kelvin, if you want to take over...be my guest.

 

[areonic1]

But Im scared if I put more into it, it will just blow out again, like it was doing mid way through this exceptional adventure

 

[Iron Weasel]

Well, unfortunately, you've reached about the end of my A/C knowledge.

The only things I can think of that would cause the high pressure valve to let loose would be a clog somewhere in the liquid (high side) line that's causing the pressure to build up and the valve to vent. Or...the cycling switch could've crapped out causing the compressor to stop and then the valve to vent.

I'm truly out of other ideas....

 

[areonic1]

Kelvin you still around? I sent you a PM

 

[areonic1]

I just got back from the parts store to get an AC clutch cycle switch, only one they had in stock was an R12, which at first was like wtf!, but i took it out to compare to the one on the car, and it pretty much looks the same...How much of a diff, or what is the diff between the two?

 

[Gus Gorilla]

If I could step in a little I've got some direction. I don't know the difference of the R12 R134A sensor. Sorry.

Since it's later in the day If your thinking about calling it quits for the evening let your truck sit overnight. In the morning go out and check the pressure without touching anything. Don't start the engine, nothing. The pressure at rest of an R134a system will follow in the ballpark with the ambient temp. At 77 degrees F a correctly charged R134a system will have 77PSI. This is where the PSI to Degrees F charts intersect. This is At Rest with a cool engine mind you. If you've ran the system this might not apply. Above/below 77 the correlation starts to walk away from each other, but not too much.
If you are still well under the PSI/degrees measurement then add some. If well above then to remove some would be best.
If you are roughly at the right pressure then run the system and measure the pressure. the low side should fluctuate as the compressor cycles.
This will get you in the ballpark for the charge level that should be in the system. Once you know this, a large part of the diagnosis is handled. Low or Hi charge causes all kinds of nonsense. If the charge is correct then this is ruled out and the focus can be turned to components.
If the low side keeps dropping too low, (lower than low 20's) then the LO cycling switch may be to blame. If it never drops too low and the clutch cycles with LO side in the HI 30's or higher then the HI pressure switch is cycling the compressor and this is bad. It is in self protect operation and not normal operation. This is all assuming a correct charge level.
If cycling in the HI 30's or higher then there is either a HI side restriction or a condenser problem.

If you do chose to take it back to a shop don't take it to that one. A good apprentice or intern can diagnose an A/C system with nothing more than a set of gauges and his hands. The lack of professional integrity you experienced is inexcusable. Refusing to show test results means they are hiding something or did not really do the test.

 

[Delta_1980]

does the system blow off every time you drive?

have you checked your fan clutch at the front of the engine?

 

[areonic1]

Delta,

What seems to be happening is: The high side is getting too hot, which is causing way too high pressure in the high side. I got somene to let me use a guage, and it was between 300-400 psi. But when i sprayed the condenser with the water hose, the entire system changed the way it was acting, the ac temp dropped waaaaayy down out the vents, the pressures dropped etc. Then went back to crap when the water went off and such.

I just wish there was a way to test a condenser before I go buy one.

Regarding the fan, Im not sure how to test that or what its suppose to do, it does come on when you start the car though, although it does seem a lil slow, least it doesnt blow as hard as my other cars have done in the past. But what does the AC clutch do, and how do you test it, if you can.

 

[Delta_1980]

areonic1

OK, the ac clutch is electric/magnetic and is attached to the ac compressor- this is not the fan clutch. the fan clutch is an aluminum part that the fan blades mount on. this Fan Clutch is controlled by a bi-metal temperature switch built into the F.C.(f.c. = fan clutch from now on)

If the f.c. goes bad it will no longer engage and allow the fan to pull enough air to cool the condenser and radiator.

to test: put on a thick glove or wrap hand with a shop towel and slowly apply pressure to the fan blades as they spin at idle. if you can stop the blades and then spin them backwards(not a necessary step) with the engine running the f.c. needs to be replaced. do this just like you did when you were a kid and you were messing around with your parents desk fan.

a new condenser will not need to be tested as there is a very small chance that there will be a defect- no moving or electrical parts. but if you draw a proper vacuum and let it set for 30 min you should be able to tell if you have a leak.

good luck, keep us updated on your progress!

 

[areonic1]

Alright, so I just want to make sure. Your saying, in NORMAL operation of the radiator fan, it stays on as soon as you start the car, BUT is suppose to speed up when the car gets hotter?

If thats the case, mine only stays at one speed and never changes when the cars hot or cold.BUT if you put a piece of paper on the condensor, it holds up, barely but it does hold up.

 

[areonic1]

Alright, I have an update. I did what you asked, by doing this.....

Run engine at a fast idle speed (1000 RPM) until normal operating temperature is reached. This process can be done more quickly by blocking off the front of the radiator with cardboard. Regardless of temperatures, unit must be operated for at least five minutes immediately before being tested.
Stop engine and using a glove or a cloth to protect the hand, immediately check the effort required to turn the fan. If considerable effort is required, it can be assumed that coupling is operating satisfactorily. If very little effort is required to turn the fan, it is an indication that the coupling is not operating properly and should be replaced.

Thats what alldata said to do to test it. Now, when i turned it off and spun it...Not sure how easy or tuff its suppose to be, but It wasnt hard to spin, but just enough pressure to make it so it wouldnt free spin. Like normaly on a free spin blade, you can spin/push and it keeps going for a few, it did stop, but it didnt take much to spin it at all.

Although, I did have an idea.....I can be like a wierdo stalker, drive down the road, hunt for an explorer parked at someones house, go knock on the door, ask em to run it so i can test and compare, as long as theyre AC and stuff works,lol

 

[Delta_1980]

yes, that just might earn you stalker status.

Try the test with engine running you'll only lose a few fingers.

This is how I test Fan Clutches and I still have most of every finger I was born with.

You could also think about installing an electric pusher fan for use in city driving-once you have your problems sorted.

 

[charli]

Hi I couldn't help but notice the fan test. There is a very simple way to test a fan clutch. Cover the radiator with heavy paper or cardboard then idle the engine. As the engine temp goes up you should hear the turbulance from the fan as the fan clutch engages. If you race the engine the turbulance increases( sucks the cardboard against the radiator strongly). If the clutch is not operating you will not see or hear any change of speed in the fan.

 

[Deleted member 128963]

Air Conditioning Forum

Here is a link that I have found to be helpful with questions about A/C.
http://www.ackits.com
They supply parts and information about various A/C problems and fixes.

Then, linked from their page is:
http://www.autoacforum.com/categories.cfm?catid=2
where you can get helpful information from forum members similar to here.

 

[areonic1]

Havent had a chance to do the cardboard thing yet, but I did go out this morning, while it was cooled down, and when i spun the blade, it had the exact same resistance it has when the car heats up