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Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 8:31 am
by DetroitAC
I agree OP's Durango likely undercharged.
I don't know why you guys have these opinions about 1234YF, it's not my experience. The charge window "length" is about the same as 134a, usually 100g. I worked on this condenser.
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 8:37 am
by Tim
DetroitAC wrote: ↑Fri May 06, 2022 8:31 am
I agree OP's Durango likely undercharged.
I don't know why you guys have these opinions about 1234YF, it's not my experience. The charge window "length" is about the same as 134a, usually 100g. I worked on this condenser.
My point is those single gauge discount charge gadgets. Are never going to provide someone with the proper information on their system! But they are making some companies lots of donuts.
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 10:35 am
by DetroitAC
Oops. Apologies Tim. I was referring to this idea that you need to nail the charge level within an ounce. I don't remember the charge plateau "window" size for WD/WK trucks, that testing was a long time ago and I've slept since then. It's in the range of 100 to 150g, or 3.5 to 5.3 oz
I agree with you about those cheap suction only pressure gauges.
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 10:42 am
by Tim
I believe the specific charge level issue comes from some systems with a low refrigerant capacity. When a system refrigerant capacity is 6 or 7 ounces. Being off by using those amazon products can make things worse.
When you have a 7-page thread on why I'm not cooling. I think it is beyond the ability of an internet forum to solve that person's issue.
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 11:31 am
by Najeem
JohnHere wrote: ↑Thu May 05, 2022 2:03 pm
Najeem wrote: ↑Thu May 05, 2022 12:47 pm
AC condenser was not damaged but I'm sure the line were. I was shocked when I saw how much 1234yf was lol
Do you recall whether the shop replaced the line?
Most people are unaware of how much R-1234yf costs in the current market. Honeywell Solstice, the originally developed refrigerant, comes in an 8-ounce can. That's right...we don't even get 12-ounce cans for our hard-earned money anymore.
Najeem wrote: ↑Thu May 05, 2022 12:47 pm
I put another video and it's still doing the same but about 15 secs cycle. I might just buy one can and add some freon see how it goes.
That's actually close-to-normal cycling behavior on the low side for an R-1234yf system, although the pressures are a little elevated IMHO. Presuming the gauge you have is accurate (it probably isn't, though, as pointed out earlier), and taking that into account, the
indicated pressure rises to 40 PSI where the compressor engages, and it drops to 34 PSI where the compressor shuts off. Those pressures correspond to an evaporator temperature of 41F and 36F respectively.
Although we don't know what the high side is doing, I like to see low-side pressures on an R-1234yf system a touch lower than that--37 PSI (compressor "on" at evap temp of 37-38F) and 32 PSI (compressor "off" at evap temp of 32-33F). So it does appear to me that the system is slightly undercharged.
It's particularly difficult to "top up" these systems because of the fact that they hold so little refrigerant. It's not like the "old days" where close is good enough. If the charge amount is off as little as 1/2 ounce, performance will likely be compromised. So bear that in mind. The best way to recharge is to recover what's in there now and then recharge to the exact amount called for on the under-hood decal. A competent A/C shop can handle that for you.
Najeem wrote: ↑Thu May 05, 2022 12:47 pm
To my understanding if it was low the psi should drop under 30 when compressor is on but mine gets to 35 then turns off up until about 42 so isn't that fully filled?
Not necessarily. The pressures, which can give us clues about performance issues, don't indicate the actual amount of refrigerant in a system. Only the weight of the refrigerant inside the system does. It seems to me that the system is a bit low on charge as I mentioned earlier.
DetroitAC wrote: ↑Fri May 06, 2022 8:31 am
I agree OP's Durango likely undercharged.
I don't know why you guys have these opinions about 1234YF, it's not my experience. The charge window "length" is about the same as 134a, usually 100g. I worked on this condenser.
So I just put one whole can of 1234yf 8oz (Honeywell) and the gauge reads exactly the same as before. Still cycling in the same range 35-43.
AC does feel a little bit colder but that could just be me and I don't see any leaks on the lines either.
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 1:11 pm
by JohnHere
Do you have an accurate thermometer (digital preferably) that you can place in the center dash vent while you're driving? A miniature spring clamp or two will help hold it in place. If you see conditioned air in the 38F to 45F range, that's about as good as it will get.
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 1:24 pm
by JohnHere
Eight ounces on top of what's already in there could be much too much. The high-side pressure would give a clue, but we don't know what that is. Because of the potentially high pressure on the high side, a burst hose is a real possibility. Please use extreme caution when working on this, and wear good eye protection and sturdy gloves.
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 2:43 pm
by tbirdtbird
Despite our advice, he persists.
Many many rules for mobile air. One is to never charge without a high side gauge for the reasons you mention.
Everybody thinks its cool to connect up a can of freon and watch a needle somewhere bounce around and have the can get ice cold to the touch, kinda like an arcade game, or a CO2 cartridge from a pellet gun. HaHa....
Only this ain't no game. Arcade games can't blind you. An over-pressure AC system can. The rapidly expanding liquid refrigerant will freeze-burn your corneas and you will be blinded. Permanently. So you can forget about that IT masters degree
From the celebtimes.com:
"If the system actually vents any liquid freon, that liquid will instantly freeze anything it touches as it rapidly boils. And if that 'something' that the liquid freon touches happens to be your eyes, you can become permanently blind."
Re: AC compressor keeps cycling every 5 secs
Posted: Fri May 06, 2022 6:41 pm
by Najeem
JohnHere wrote: ↑Fri May 06, 2022 1:11 pm
Do you have an accurate thermometer (digital preferably) that you can place in the center dash vent while you're driving? A miniature spring clamp or two will help hold it in place. If you see conditioned air in the 38F to 45F range, that's about as good as it will get.
So I put thermometer and the lowest was 48F while driving and outside temp was 48F as well. I will use a real gauge tomorrow and check both low and high ports.
Re: AC compressor keeps cycling every 5 secs
Posted: Sat May 07, 2022 7:10 am
by Cusser
Najeem wrote: ↑Fri May 06, 2022 6:41 pm
So I put thermometer and the lowest was 48F while driving and outside temp was 48F as well. I will use a real gauge tomorrow and check both low and high ports.
Outside temperature is 48F ???? How the heck can you check out an AC system then ????