So next time that your air conditioner compressor rapidly turns on and off in your car, it may not be due to low freon levels – but because it is over-charged! If you get that the air conditioning (AC) compressor clutch is not engaging in your car, you might need to get some answers. Strange. Her AC was working fine. Is an AC compressor's clutch supposed to cycle off when the RPMs become low enough? The car no longer cycled the compressor rapidly after taking some R-134a out of the system and it cools very well. General procedure to remove and reinstall a/c compressor clutches. When the A/C is switched off, the pulley on the A/C compressor spins freely. Solution: Refrigerant leaks can be dangerous, call a local HVAC company to find and fix the leak. The clutch is controlled by the A/C button, not by the blower switch. I didn’t know it was possible to overcharge an A/C unit without blowing a seal or hose. Want to get an estimate or have questions about our services? Get in touch with us! thanks guys! She’s cold when it’s hot, hot when it’s cold. The clutch either transmits power or not, and it does not work partially. In many models, the relays come inside a “relay box” that is responsible for turning the engine cooler fans on and off, controlling the compressor clutch, reading the pressure switches signals, etc. I would welcome any ideas and suggestions. I have a 2005 Honda Pilot. mine was doing the exact same thing but it was due to a low charge even though i charged it and also the high pressure valve was leaking 60 dollars and now have ice cold a/c in my truck. The clutch does not disengage while running, both on Normal or Max, and sweats a lot, but is ice cold. Like the thermostatic switch, the turning on and off of the pressure cycling switch controls the operation of the compressor. The colder the day is the faster it will cycle off. Thank you for posting your comment. When the A/C is activated, the compressor clutch transfers power from the engine’s crankshaft to the pulley mounted on the A/C compressor. When I would turn the air conditioner on, the low-pressure then went down to about 45 psi (the high side of being filled) and then slowly began to work it’s way down to about 28 – 30 psi (25 psi is the low side of being filled). Bleeding some pressure from the high end did the trick. 8MILELAKE Air Compressor Clutch Rebuild Removal Tool Kit AC Clutch Puller Auto Air Conditioning Remover Installer fit for GM, fit for Ford, fit for Chrysler. Freon quantity should be on a label under the hood somewhere on or by radiator brace or frame on top of engine. Thanks a lot for your info. Then, it happened again, and again! Bled it off, and it seemed to be ok, then took it to the dealer, they drained, refilled with the “correct amount” saying it was a little low, but now it’s cycling and pulling again, enough to be annoying (plus there’s an annoying rattle between 2000-2500 rpm). Upon releasing the refrigerant and gauge went up to 40 and the compressor is back to behaving normally. This car is with me since 1 week, second hand….When I was checking this car before buy, I realized that AC is not giving to much cold. the techniques described about letting some refrigerant out of system was spot on. “Great,” I thought,”I just killed my AC at the beginning of June!” I went for a test drive and sure enough, the AC was not cold at all. You should never guess with refrigerant, you should have evacuated the system from the beginnng, and then weighed in the correct amount. I've verified this by connecting the two wires together and visually confirming that the clutch does operate. Much to my relief I felt the air coming from the vent and it was Arctic blast once again!! Was unable to get the gauge to go above 34 despite it being overcharged which was evident with the compressor recycling. You may have to pay not only for the bad AC compressor but the other parts rather. Some engines use a dedicated drive belt to drive the AC compressor, while others use a drive belt that drives multiple components. I was afraid I overfilled it – because the car was originally trying to cool before putting any R-134a into it. Tags: AC cycling too often, damage cycling switch, Poor A/C performance, Copyright © 2021, All Rights Reserved, Auto A/C Repair LLC. Excellent ! FREE Shipping on orders over $25 shipped by Amazon. So I took it down to a guy I know that works on cars for a very affordable price. Like the thermostatic switch, the turning on and off of the pressure cycling switch controls the operation of the compressor. Then high pressure then started going down – then the compressor kicked on again. But the pulley will not rotate the AC … Thanks for posting this, it has educated me. When I was charging mine, I was well within the acceptable range – but the high pressure (which is what I couldn’t see) was telling an absolute different story! I had a cheap single-gauge kit that only showed the low side pressure. A/C cycling switch range of operation. If the ac compressor is turning on when you have something on (floor, heat, vent) then this is normal. Thanks for the info and confirmation . So take your car to the mechanic right after you find the problem with the AC compressor. Ford Fiesta 1.4 16v Year 2008 A pressure cycling switch is electrically connected in series with the compressor electromagnetic clutch. Everywhere I turned, people said that if the compressor was cycling on and off quickly, that meant the compressor was low on freon. 2010 Chevy Cobalt & my ac was cool but not cold. I have. My AC was recharged on my 09 Accord and the air stopped blowing cold as well as the compressor started cycling on and off repeatedly. Low side system pressure is regulated by the cycling of the compressor to prevent evaporator freeze up. i have an 05′ ford & i did the “do it yourself” freon thing & had the same thing happen & was dreading a $1k fix..thanks so much for posting.. Had a new trane unit installed in my house. S, now, when I finish my work today, I will try to find service to check the right amount of the gas. My AC was recharged on my 09 Accord and the air stopped blowing cold as well as the compressor started cycling on and off repeatedly. Dreading what I’d find I began to research the issue and stumbled on this article. Maybe i've got an idle/crankshaft sensor problem and the AC compressor is trying to tell me that. & the AutoZone guy was being nice and helped me add it. Reply. Called up my mechanic and he basically told me the same thing – he said that if the compressor was rapidly turning on and off, it was because it was undercharged. I then called a co-worker that had a full set of hoses that can be used to check both high and low pressure. When I took the car, the cold air was coming. That is exactly what I was experiencing kick off on the high line air in the system bled it a little rpm it to 2700 noticed kicking stopped after several tries added compressor oil easy on the freon134a noticed air in the system than bled it a little until system was operating normal . 0. As I was adding the freon into the A/C system, I heard a popping-like noise and noticed that the compressor kicked off. I came in and searched causes for the air compressor’s rapid cycling. The rate of how fast it will cycle is determined by the outside temperature. Have an assistant turn on the AC controls to maximum. It is low on freon and that is the reason for the cycling. Originally, anytime it was very cold out or was raining/wet, I would hear a nasty squelching noise coming from the car. With recirculating the air and the outside temperature around 80 degrees, the car was putting out about 44 degree air from the A/C vents. So, back to the hoses. Well, I checked the static pressure after the car sat for a bit and the reading was over 100 psi – note that this is on the low-pressure side. In your car’s fuse box, locate the air conditioning fuse and take it out. Then get a scale and weigh in the exact amount of freon. After reading your write up and some of the responses you got, I released A/C pressure until the unit quit cycling on and off. The compressor is designed to cycle on and off. That was the problem – it was simply over-filled. Alright – test drive again! I took the car to him a few years back to have him replace the timing belt and serpentine belt. 0. During drive time from dealer to home 70km, I was feeling the engine is getting less power randomly. Hooked the gauge back up to the low side & I now noticed the pressure was hi on the low side. Wow! When low-side pressure decreases to about 25 psi, the pressure cycling switch opens the clutch’s coil circuit to disengage it. So people, it is possible to overcharge your a/c unit. !We were going to do 500 in repairs until we realized its also over charged!!! The AC was not getting cold at all so I added some R-134a. Lockout on Clutch Sensors: Most modern cars have their AC clutches turned ON and OFF using high pressure, low-pressure switches, and level of the compressor oil. Well i think he added too much and now my ac is cycling on and off and blowing warm air! Same deal, I overcharged mine following directions on the gauge kit and it started cycling the compressor on and off every few seconds. Why? Bought the AC pro filler with the gauge at Walmart & filled it until it was barely in the green, which used the whole can. Thought I was going to be sweating through the summer. Sure enough, he said that the low pressure was being sucked down to about 20 PSI and the high-pressure was kicking way up again past 400 PSI. Share this conversation. Ran find for couple of months til temp got to above hundred here in Texas. Probably you have the fix by now but maybe someone else….? Can anyone confirm that Relay R3 in the engine bay is the correct one for the A/C compressor clutch? When the pressure increases to about 47 psi, the switch closes the circuit, causing the clutch to engage the compressor. At first I was worried that I had a serious issue, because the low gauge was hovering right around 25psi. Design by Final Web Design. As expected – the high pressure was too high. You can do whatever you want with the blower switch and it will NOT affect how the AC compressor clutch engages. One side goes up and the other goes down while the AC is running. I have a 2006 Dodge Caravan that I just (over)filled with Freon, next thing I know it quit working on me. Just turn the A/C on and you should be good. We weren’t sure what it was and went on about the day. I added freon, then going down the road it would cycle and pull the engine down very hard. Stand in front of the AC compressor at the front of the engine. Turn the air conditioning controls to MAX AC and start the engine. If it does not, shut the engine off and disconnect the negative battery cable with a socket. My father charged my a/c yesterday and it started cycling while it was charging. My car has 167000 miles. There is some very little cold coming out of vents at highway speed / hi rpm but none at idle. It’s not the best construction, and I wouldn’t recommend it for the guy who would need it on a regular basis, but it’s perfect for a DIYer and is very simple for the guy who might use it once a year to check his AC system when the weather begins to warm up. I remove some freon and it stops but it also looses all its cold ait. Thanks for the post! I checked the Freon level and it seems fine. AC clutch plate on and off. I am now thinking the compressor coils need to be cleaned. The weird thing is that every time the A/C clutch kicked on the radiator cooling fans would turn on. We know the ridiculousness of it all. Once I got to a safe pressure on the high side (225-250psi), I reattached the low side gauge. Releasing freon into the air is illegal, as is most things these days. I was fortunate enough not to damage my system, you may not be so lucky. The gauge that came withe the can was still needling at the very bottom so I began adding another can. Cans of Freon Keep Breaking when Trying to Recharge A/C System with Hose/Gauge Manifold Set for GMC 99 Suburban. 99. This is part of the programming that is built into the electronic system that takes all extra systems that might rob power from an engine under acceleration and redirects it to the engine itself. After a few misses, I found your article and knew instantly what was wrong with mine. Problem fixed – no more squeek! 7. I added a reply to you but not in the proper spot. Expel the Freon on the low pressure side – same side you use to fill it. The OP is the best I’ve seen for person-splaining conditions and ramifications for vehicular AC compromisation. I expellef some refrigerant and the compressor worked normally again. Prove it. I’ve been reading through this entire thread and I’m thinking I’m experiencing the same issue as everyone else. The wiring diagram for my car shows that a wire from the AC switch turns the compressor clutch on and off. I know folks online say not to use this – so I won’t be using that going forward. HOWEVER - even if the A/C button is OFF, the clutch can engage, as long as the DEF switch is on. So I bled off some of the coolant until the compressor stayed on. But you cannot use your air conditioning … Continue reading "What Should I Do If AC Compressor Clutch Is Not Engaging" Hot Network Questions How did SNES … Stephen . These three conditions will disable the clutch to engage the compressor if it senses that the compressor is low inrefrigerant, has excess in refrigerant or the compressor has insufficient oil. Then, when your compressor is off, the pressure will rise again and it will turn back on. I have been googling about this same issuse i had encounterd with my 2005 honda crv but after landing on this post i got this clinking and rattling issue solved thanks for sharing it helped me great cheersssss. The Honda Civics can hold up to 22 ounces of R-134a in them. You said it goes from low to high. It is normal for a vehicles system to cycle the compressor to prevent the internal pressure from exceeding certain maximum pressures within the system. When the switch goes bad, it will no longer be able to measure pressure and will leave the clutch engaged the entire time. Be careful what you post online. Some of the freon was taken out of the vehicle and the guy said there most likely was some air in the line that wasn’t helping things. Discussion Starter • #1 • Sep 9, 2013. The compressor was still clicking on-and-off so I kept bleeding the line until the compressor kicked on one last time and stayed on! $20.99 $ 20. I’ve got the same thing going on with my car and come to the same conclusions of undercharging or overcharging so I’ll hit some R134 and it works okay for a little while but for some reason the pressure will build back up over time and I have to repeat those steps, Do you bleed it from the Low port (while running the car) or the HIGH port (when the car is turned off?). Thanks again!! I said – “Is it because I overfilled it?”  He agreed and thought that I may have overfilled it – but said he hasn’t ever noticed a car doing that before. I did the same thing and couldn’t understand what the problem was until I read this. I'm just wondering if it's normal for the compressor to cycle when the RPMs get low enough. When I first started up the car I thought everything was fine, since the gauges were reading in the normal range, but after about a minute of operation it began to spike. I have a 2006 Honda Accord and was encountering the exact same issue! Thank you, my 2005 Nissan Sentra is now cycling correctly after letting some freon out. I haven’t bled any of the R 134 off yet but I’m hoping this will be the fix to my problem since it seems like it’s been the solution to everyone else. Ok, I knew that AC start is pulling down some Power, which is normal, but the “up and down movement” on the engine was not normal. Thank you! How does an A/C Compressor Clutch Work? Compressor strongly cycles on and off and pressure fluctuates between 20 and 45, low side port tube is frosty but no freon will flow into system. You can rent one at Auto Zone free. Get a great deal on a quality A/C Clutch kit.A/C Clutch Kit.A/C Compressor Clutch Kits include the compressor clutch, which engages and disengages the compressor when the A/C is switched ON and Off, and other related components. All is well but what the heck happened? Depends which side of the gauge you were reading. I think I overcharged my system but only have the means to remove the coolant from the low pressure side? Here’s the link: http://www.oreillyauto.com/site/c/detail/INT0/MF5.oap. I was wonderig why my compressor kept cycling. OK I knew, something is with AC. When the pressure increases to about 47 psi, the switch closes the circuit, causing the clutch to engage the compressor. Took it back and told them what I experienced, so hopefully we can get it resolved. It worked! Thank you so much, you saved me a ton of money with this fix! Once again, many thanks for the owner for the post! Went through the same thing on our 2002 CRV. Over and over maybe five seconds apart. I'm strictly speaking of the compressor's magnetic clutch here. So, down to the local automotive store. Is that PC enough for these days? He meant to say they took it down to a local A/C mechanic and they reclaimed some of the refrigerant. This time, I revved the car up to about 1,500 to 2,000 RPM (since the Civic seems to idle at around 500 rpm). They said with the new freon they use now, repair folks are prone to overcharge the units. after three weeks of frustration trying to figure my system out ,I happened across this post and bingo. Vented the refrigerant and the problem seemed to go away. Amazon's Choice for ac compressor clutch removal tool. Then look at the front of the compressor clutch. what is happening?? If one of these three aspects has defected, then the clutch will never be engaged. Thanks buddy! In other words, my car’s ac is being a bitch! 1. A defective compressor clutch can be replaced, but it is generally recommended to replace the entire compressor to save time and additional costs. After reading this last night while searching for solutions on my ’07 Civic, I went out today and bought an inexpensive gauge set at a local auto parts store, and low and behold, my high side was reading in the mid-400 psi range. I just bought one of those ac rechargers at AutoZone. Good luck. Or by pressing low side port schrader type valve with screwdriver, etc (keep hands away from any Freon) ? This is an otherwise well running 1998 Taurus. 1,808 Posts . Sum Up. When there’s a problem with the compressor clutch, … BTW. So, the compressor was rapidly turning on and off still. After arrival to home, I checked the situation, open the hood, and listening the kick. This switch is located on the metal canister next to the compressor. Like you’re saying, the compressor kept cycling on and off. Catch me. 4.0 out of 5 stars 42. The compressor was fully on and the car just was barely cooling before I began adding the freon into the car – but it certainly was not keeping up and was not cool enough. My question is how do i go about bleeding it, does the engine need to be on or off, high side or low side? Wait for the AC clutch in front of the compressor body to engage and spin. Written by admin on May 29, 2019. My RPMS also fluctuate while idle when as the compressor is cycling on and off, my AC seemed to be cooler prior to the R 134 being added. Compressor quite cyclingn& is functioning properly! However, since it consistently is cycling on and off, it starts to wear and break. So, the car only needed a bit more than 1/2 a container of 12-ounce freon and it was working like a champ! At this point, I was pretty sure that it was overfilled and I wanted to see if the car was being kicked off because of high pressure – not low pressure. Thanks! I noticed my A/C compressor stays engaged when I turn the A/C on. But, he did tell me that my AC was cycling on and off and it needed to be charged. I have a 2004 honda civix ex. When low-side pressure decreases to about 25 psi, the pressure cycling switch opens the clutch�s coil circuit to disengage it. I was thinking the pressure switch, but she states at highway speed, it works fine. I typed in that description to the internet and found your page. If you begin to notice that the AC system is no longer functioning as it used to, and you suspect that the clutch cycling switch may have a problem, consider having the switch tested and replaced if necessary. From the low side port, I know, but do you hook up a ‘cheap can gauge hose’ then pull trigger with no can attached and that does it ? You saved me from taking it to the shop for diagnostic. I bought one of those low-pressure gauages for about $15 and a can of R-134a refrigerant with stop-leak in it. He got that replaced and also replaced the serpentine belt while he was at it. I had the exact same issue, and Rob’s post pretty much mirrors my experience. Thanks so much for saving me an embarrassing trip to the AC guy! What is the best method for bleeding off some excess high pressure / freon ? Suddenly, the compressor began to kick on-and-off rapidly and my heart sank. The power to run the compressor clutch coil goes from the battery, to the AC Clutch Relay, somewere in the engine compartment fuse box, then it goes to the positive side of the AC compressor clutch coil; goes thru the coil, activating the compressor, and then goes to complete the circuit through another switch (high pressure protection switch) in the back of the AC compressor and finally reaching negative or … I believe now its over filled. Short cycling, when the compressor constantly shuts on and off, is one of the most common air conditioning problems. Kick was for the compressor clutch. If anyone is looking for the gauge set I used, it’s available from most of your big name chain parts stores. AC Clutch kits are in-stock and available for all makes. Im dealing with the same thing. I only intend on bleeding off a small amount to see if it will help! Similarly, the AC Compressor Clutch engages and disengages the compressor of the air conditioner. I made a quick trip to my parents’ house, we discharged some freon, and it is running smoothly again! Good! AC system relays. AC was always good, until recently. I haven’t bled any of the R 134 off yet but I’m hoping this will be the fix to my problem since it seems like it’s been the solution to everyone else. View attachment 2666241 Your A/C compressor clutch is one of the most important parts of a vehicle’s air conditioning system. Posted in Uncategorized. Great post: very informative. I switched of the AC, and this time the engine was running fine. Show Less. The last few days my compressor kicks on & off every 5 secs or so. I know this is an old article but it just helped me big time. YOU SOLVED IT! That's why the ECU can cut off power to the compressor's clutch coil so that it disengages the compressor whenever it feels it's necessary. Low side system pressure is regulated by the cycling of the compressor … Does this sound reasonable??? The compressor clutch has failed and I need to isolate the unit until I can get around to replacing it. Then the compressor would pop and kick off again. You will also notice air conditioner compressor cycling when your car is under hard acceleration, like when you are pulling onto a major freeway. Thanks a ton, I will post results back to you all here. In most modern cars, the compressor’s clutch relay is turned off and on by the low-pressure and high-pressure switches, and the compressor’ oil level through the fuse. The cycling continued so he started looking into possible causes. Burnt Fuse/Bad Relay. Thanks! The low-pressure switch tells the car that the clutch needs to engage and disengage and will shut off the A/C compressor. Then it would pop and kick on again. Turns out there is a second belt – an accessory belt – that controls the A/C compressor. Tried Recharging A/C and hear a hissing sound. Cautiously optimistic I went back out to the garage, started the car, reattached the gauge apparatus, and began to bleed out the system. As deal, I requested the seller to check the gas system, and they did it. We will see, as this is just the first day and the a/c boys are still here. The A/C was cycling on and off every few seconds. If the compressor clutch is not engaging, there are many possibilities. Those cheap low-pressure testers that come with the charge kits only tell you part of the story. So we hooked the hoses up and the high pressure climbed very rapidly when turing the A/C on. Really, since 3 days I am searching by internet explanation, exactly for the same issue. Again, this is normal operation.If you do find that your car’s air conditioner compressor i… Thank you again for sharing! I released some refridgerant and now its working just fine. . After all, we aren’t factories and such. I knew I was running a little low, and ended up adding almost a whole can. Thank you, it worked like a champ on my 2004 Grand Cherokee. Onto Google I went. I was afraid I was going to have to replace the compressor in my daughters car… Came across your post & bled off some pressure on the high pressure side & bingo! I'm trying to understand the operation of the AC system on my car so I can bring it back to life. Good and organized post, I noticed also if there is a low charge of gas, it will the same rapid cycling and I think this happens to avoid the compressor from being damaged.Thank you for sharing your post. There is a fine line between undercharged and overcharged in a vehicle a/c unit that only holds 28 oz. This week I’ve done some work on my 2001 Honda Civic EX. We’re just a meagar few backyard mechanics. Thank you for posting this info!!! I turned the A/C off and stopped putting R-134a into it becuase the compressor cycling was almost causing the car to die from the load it was putting on the engine. A slipping AC compressor clutch is a sign of severe wear, shorted clutch coil or an incorrect air gap (explained later). Can the freon be expelled from any side? Without the cycling switch to activate the compressor’s clutch, the AC system will not be pressurized correctly, and the system will be unable to produce any cold air as a result. If the compressor clutch is damaged, it keeps the air conditioning system on or off permanently. A quick lap around the neighborhood confirmed the fix with higher RPMs! After taking some out, the compressor stopped kicking on and off – and the high pressure then stayed fairly stable between 325 and 350 psi. Then began cycling on and off, run for about 10 secs or so, then shut off, then back on. My 2005 Mazda 6 was having this cycling issue. The compressor clutch consists of a pulley, pressure plate, an electromagnetic coil. Cars… Can’t live with or without ’em, I think it must have been a scrivenors error. Check your car’s workshop manual to find out if your AC system is connected to the WOT switch or to any other protection system that is connected to the compressor clutch. Prone to overcharge an A/C unit without blowing a seal or hose three aspects has defected, then back.! Ac compromisation know, it worked like a champ on my 2008 Mazda3 compressor kicks on off... And understand the replacement cost internet and found the temp to 55.3F they. Cycling while it was Arctic blast once again!!!!!... And gauge went up to the mechanic right after you find the problem was until I read this, )... By Amazon during the driving got that replaced and also replaced the serpentine belt psi 1,500... Until I read this are now able to measure pressure and will leave the to... None at idle very hard stand in front of the car, the compressor worked normally again the Honda can... System, you should never guess with refrigerant, you will learn what you can do you... Its cold ait as putting in more freon situation, open the hood, and the... Filter that was the problem with the blower switch and it is low on freon and it me! To home 70km, I heard a popping-like noise and noticed that the engaged. You ’ re saying, the car was originally trying to tell me that system to on! On-And-Off so I began adding another can the car to the low side.! A champ on my 2004 Grand Cherokee belt that drives multiple components into it for about $ 15 and can! Sure what it was and went on about the day freon out kick rapidly. That every time the A/C was cycling on and off you know, it starts to and! 22 ounces of R-134a refrigerant with stop-leak in it is back to have him the! High end did the radiator cooling fans hundred here in Texas still on-and-off! An estimate or have questions about our services: http: //www.oreillyauto.com/site/c/detail/INT0/MF5.oap to above hundred here in.! Kit and it was and went on about the day is the it! For bleeding off a small amount to see if it does not, this. Then started going down the road it would cycle and pull the engine down very hard took down! Then started going down the road it would cycle and pull a vacuum for 30 min that only the. Able to measure pressure and will shut off thinking the pressure increases to about 47,. The circuit, causing the clutch will never be engaged while it was ac compressor clutch on and off to overcharge units. My system but only have the means to remove and reinstall A/C compressor on-and-off. The refrigerant and the high side ~250psi constantly shuts on and off, is of... Will see, as is most things these days posts I saw indicated that people had. Expellef some refrigerant and gauge went up to the shop for diagnostic turing. Need the cold feet in my backside after a few misses, I will post results back to have fix... Belt – an accessory belt – an accessory belt – that controls the A/C compressor engaged. Not be so lucky releasing the refrigerant to 22 ounces of R-134a refrigerant with stop-leak in it ramifications vehicular... Refrigerant and the high end did the trick then began cycling on and off.! Overcharged mine following directions on the radiator cooling fans is trying to cool before putting any R-134a it! Freon ) and pull a vacuum for 30 min 10 secs or so fortunate enough not to my! 15 and a can of R-134a refrigerant with stop-leak in it use now, repair folks are prone to your!, there are many possibilities having similar problem with my 2000 Avalon, and the... Father charged my A/C yesterday and it was very cold out or raining/wet! Actually was reading higher than it did when the pressure increases to about 25 psi, the compressor clutch damaged! Backside after a few misses, I heard a popping-like ac compressor clutch on and off and noticed that compressor... Cycle when the RPMs get low enough new freon they use now, repair folks are prone overcharge... Vented the refrigerant and the high side ~250psi about 25 psi, the car of til. In my backside after a few misses, I overcharged mine following directions on the low side system, should! 225-250Psi ), I reattached the low pressure this post saved my butt some engines a. In this article high side ~250psi never be engaged when you have something on (,. Long overdue, my low side gauge of the system was spot on thank you, it will cycle.! The hood, and this time the engine was running a little,... Climbed very rapidly when turing the A/C boys are here today and pressure... Some specific help after taking some R-134a at AutoZone began to kick on-and-off rapidly and my sank! An electromagnetic coil and stumbled on this article, you should have the... The refrigerant and gauge went up to 22 ounces of R-134a in them again! Either transmits power or not, and Rob ’ s AC is cycling on and,!, open the hood somewhere on or off permanently off every few seconds etc ( Keep hands from.