The clutch disc is attached to the shaft of the … When the compressor clutch is engaged, a current move through the electromagnetic coil. Something on my car is telling something the A/C should be running. Even when the pressure should have made it turn off. Please confirm this so we can continue. I suggested some testing in my last response. My A/c Is Blowing Hot Air. I have the same electrical gremlin in mine. GLYN, if you get any further along, please post it here. The colder the day is the faster it will cycle off. That depends on the car. If the A/C clutch relay is stuck or the switch is faulty then the clutch will stay engaged. It looks as if the ECU is programmed to disengage the clutch automatically whenever the engine RPMs lower too much, but i never found anything like this in any documentation about automotive ac systems i read so far. I am really starting to give the new pressure switch the stink eye. I saw that, and amgoing to try that first. I understand that when using A/C and the compressor goes on and off too frequently, that the freon might be low. If the clutch spins freely at all times, and the compressor never comes on, then it may not be engaging and therefore needs to be replaced. The noise is a whirring sound. At 35, the clutch will stay engaged. Will try to find a while during the week end to see if it can be fixed. In most cases, when the AC compressor and clutch engage, it will draw extra ’power’ from the engine and cause the idle to slightly drop. The clutch is controlled by the A/C button, not by the blower switch. The rate of how fast it will cycle is determined by the outside temperature. Start the engine and turn on the A/C. This will allow the compressor drive and the engine to rotate at the same time. I have a spare stock Nissan one and I am going to try that next. Same thing : AC clutch engaging an erractic way with blower switch off and AC button on. I get good heat and excellent cold. Small cars typically have stacked AC and engine radiators cooled by a single fan. had the ac serviced at perry tech last summer. Very weird! If you can name it, I have changed it. Turn the air conditioning controls to MAX AC and start the engine. A bad AC compressor clutch needs immediate fixing. :-/. It sends a signal to the ECM to turn on and when you turn off the A/C, the signal is still being sent. Seems to me right after I rebuilt the entire AC system, I had rapid clutch cycling. Thank you. HOWEVER - even if the A/C button is OFF, the clutch can engage, as long as the DEF switch is on. I have a 2007 Hyundai Tucson. That is why it disconnects when you remove the wires from the low pressure switch. This situation is dangerous due to the serpentine belt powering not only the AC unit, but the vehicle's charging and cooling systems as well. Watch what cleaning agent you use as a lot of those will literally melt any plastic they touch. When the AC is off the pulley and bearing are still spinning. It's Like There Is A Blockage. I swapped out the complete control head with another today and same deal. I have replaced; compressor, dryer, expansion valve. When power is applied to the clutch it engages to turn the compressor. That is the first good idea I have heard yet! Bought this car about 6 months ago and its finally getting hot enough to test the AC. If I touch the the blower switche and gently shake it (more or less gently, depend on how is my mind at the moment), still on off position, lights comes off and clutch disengage... Further information on the defrost cycle. An air conditioner clutch that repeatedly engages and disengages is usually an indicator that the vehicle's system is low on refrigerant. With the ac off your clutch the outer non belt driven part will not be turning. And I have no desire to figure it out either. I have this exact issue haunting me right now. Best way on earth to keep the fog off the windows. I Don't Hink This Car Has A Cabin Filter. I've fixed several by taking them apart and cleaning. I even get both fans running too! pfffffffff, so, one more spare part to buy... Will do so. Ken, I removed the signal wire running from the relay back to the ECU. It then immediately re-engages as soon as the RPMs start increasing again. A/C clutch engaged all the time. From all indication you may have a bad control head. I notice, however, that the clutch plate engages and disengages fairly regularly (may be every minute). I will do you one better Ken. On off A/C switch in passenger compartment does not light up. O'Reillys said I probably got a faulty switch from them. Did not want to charge the system if there is refrigerant at the correct level. Want Answer 0. This condition can usually be remedied by simply unplugging the wire that connects to the clutch if the expense of actually repairing the system is too high. In some cases, a vehicle may idle poorly when an air conditioning compressor clutch engages, which is typically due to the extra load imposed by the pump. I installed a remanufactured AC compressor and the clutch makes noise when it is engaged. A delay can cause serious damage to … Motor running, AC on max, fan on high. Let me just reiterate, I did find a wire crossed at pressure switch to make the compressor run 100% of the time (fixed) The compressor, pressure switch, expansion valve, dryer have all been replaced, system has been evacuated, flushed, but the pressure is running to high on the high side. Okay, Let me start over, I have had my vehicle to shops. Why Do I Have White Fog Coming From Air Vents Even When Air Is Off. The AC clutch is on the front of the compressor where the belt rides. A failed electronic clutch on a vehicle's AC compressor can lead to the freeze up of the AC pulley which, in turn, destroys the belt. 1993 Chevy Silverado 3500 6.5/4L80E, 4.10's. That is a good one, I have the wiring diagrams here and I am looking over as well, you can confirm that when you remove the ground (pink wire) from the ECU the compressor turns off? Compressor clutch disengaged and both rad fans stopped running. On this note has anybody experienced the AC light coming on when their button is out? Who knows, maybe the new ones are not wired correctly? The ac pump runs with defrost as it dehumidifies the air, assisting in defrost/defog of the cabin air. There is a writeup over at jeepsunlimited.com about wiring the pre-91 AC clutch so that more voltage gets to it thereby kicking it on. Most AC clutches are designed to spin freely when disengaged, and also with the pulley and compressor when those are engaged. Whether the clutch operates or not will all depend on the AC itself. Okay, do you mean if you have less than 20 lbs of pressure on the low side, the compressor is still engaged? I will remove that signal wire from the ECU from the relay tomorrow and report back my findings. AAMCO recommends having the system checked and charged, as operating an air conditioning system in this condition causes further damage. Is this normal or did someone rewire the AC controls? Come join the discussion about duramax engines, performance, builds, modifications, classifieds, troubleshooting, maintenance, and more! It just seems to me that 13V SHOULD be enough. Hence, the AC starts working. The interior switches collect lint and tiny particles of dirt/grit from the air and sometimes are "interrmittant" in operation. I have no problems with the A/C, but when I use the heater (more often) the compressor turns on and off too frequently. On the other hand, i've read that the clutch usually gets disengaged temporarily whenever a … had a can of coolant hooked up checking preasure. Still another air conditioner clutch condition that you might feel, more than hear, is a slight vibration when the air conditioner clutch disengages when you are idling at a light or if your vehicle has reached the temperature you want. 97 K2500 Suburban, 3.42, 265 Tires, Custom Oil cooling lines, Snorkel removed and 4" Heath Exhaust and crossover. Hello, thank you for writing in. The AC is not "on". Will low refrigerant level cause the AC compressor clutch to not engage 15 Answers. I have spent hours and hours pouring over wiring diagrams trying to find out where this thing is getting a ground to close the AC relay. Posted by rick lee on Jul 12, 2012. The blower switches have nothing to do with the clutch engaging, in ANY GM vehicles. I have read somewhere that once the pressure in the ac system drops to a ~ AC clutch plate on and off The guy at the electric shop tried to convince me to run a ground from the relay so the compressor would stay on (all the time), not knowing I knew better. When it is off, the fanbelt just runs over the clutch and does no … So it was then I bought a new pressure switch and that was when I discovered I could never shut the silly thing off. Is it supposed to be engaging even if your in the red … I was talking with the guy at O'reillys. years ago when this was not built in we used to run the AC with the heat turned on to rid the rig of foggy windows. I Have Checked The Relay. Okay, spray some water on the condenser and see what happens. I only had that happen once, and I melted a blower switch because I figured it wasn't serious. Ac turning itself off and on. Both the pulley and the clutch should be spinning. Chris (aka- Moose) Technician. The electrical auto guy says it is a thermostatic meter. Pink wire grounding th relay. I will get one tomorrow and let you know the results. Can you test the AC switch to make sure the signal is being cut when the switch is off? He was questioning the brand new triple pressure switch I installed and wanted to get me another one. flowmaster, fumoto, chrome hummer wheels, Leer topper, blizzard 810:blizzard: high idle, awaitng secondary fuel filter and lift pump, braided stainless custom oil cooler lines, cutom boost controller, optic bump, mandrel bent 2.5" crossover,3" downpipe, 3" straight pipe, boost gauge valet remote starter,K&n filter, 285's, blizzard 810, Duramax First Generation: 2001-2004 (LB7), Duramax Second Generation: 2004.5-2005 (LLY), VerticalScope Inc., 111 Peter Street, Suite 901, Toronto, Ontario, M5V 2H1, Canada. … The compressor is designed to cycle on and off. It does this to maintain the seals in the system and circulate verything around. Yes sir, clutch stays on. If that doesn't work then I'll replace the clutch. Eighty degrees outside (Texas). Air conditioners operate as a closed system. When the AC is turned on, the clutch disc on the front of the pulley is pulled into the face of the pulley which is still spinning with the bearing. Typically, the pulley will freeze due to a malfunction in the electronic clutch or the failure of the … Now it seems to be working fine again. I just wanted to be certain there weren't any other parts or service issues I needed to be aware of … If the AC is turned on, the clutch becomes “energized” and “engages” the armature plate of the compressor belt and compressor drive. A defective compressor clutch can be replaced, but it is generally recommended to replace the entire compressor to save time and additional costs. It appears I have a ground problem, that was the answer from the A/C shop. Checked the fuse and it is good. clutch disengaging every couple seconds. Because the clutch is attached to the compressor shaft, if it becomes … Mine does it once in a while, not really worried about it just a curiosity, cycling the button cures it. It has to drop below 20 to disengage the clutch. Pressure is not cycling 35 low 150 and up on high. The noise stops when the clutch disengages. JavaScript is disabled. Just didn't want to ruin the compressor. Clutch on compressor is not turning. However, this can cause existing issues to be amplified. Most car AC systems use an electromagnetic clutch element that engages the compressor to spin the air conditioning unit. Once an electrical current from the on/off switch sends power to the magnetic coil, it causes the outboard clutch to pull in toward the compressor, locking up the pulley and engaging the compressor. I'm wondering if the button contacts are still making somehow, guess I might stock in a new button just in case. Low 35 are so, high going up to 250. The Wiring Is Showing A Current And My Compressor's Clutch Clicks And Turns When... Each Fan Speed Blows Out Much Less Air Than It Use To. Yes, trial and error we will find the problem. The center part (the clutch) should be engaged and should be spining along with the pulley. Changing the compressor clutch could be the only solution in this case. Again, this is something that should be checked out by a professional. The compressor clutch regulates when the AC compressor should be switched on and off. Compressor, condenser, evaporator, expansion valve, dryer, triple pressure switch, relays, thermal control amp, control head and even swapped the ECU! Disconnect the power wire to the clutch and apply 12 volts to the clutch field winding terminal. PROBLEM IS WHEN AC/HEATER CONTROL IS SET TO ANY POSITION BESIDES OFF, THE AC COMPRESSOR CLUTCH KICKS IN AND OUT ABOUT EVERY 3 SECONDS CAUSING THE IDLE TO VARY FROM A … read more. My air is nice and cold, has the right amount of PAG and refrigerant, but when the car starts, I can hear the clutch engaging with the system turned off. You can do whatever you want with the blower switch and it will NOT affect how the AC compressor clutch engages. For a better experience, please enable JavaScript in your browser before proceeding. If the clutch engages, then check the power supply to the clutch, including the system protection devices and electronic compressor controls. I have replaced expansion valve, dryer, Freon. I have a 98 S70 T5M. Then look at the front of the compressor clutch. An AC clutch engages and disengages the compressor when your car's air conditioning is turned on and off. A forum community dedicated to Chevrolet and GMC diesel truck owners and enthusiasts. A good test would be to unplug the compressor (whilst … I have 2011 Mazda CX7. That creates a strong electromagnetic force that pulls the … I have a work around in mind. It is a thirty degree old school mechanical switch stuffed onto the EVAP core, a relay and a master kill switch for winter use. For example, if you have dirty fuel injectors, mass air flow sensor or EGR valve on the vehicle, the activation of the compressor clutch will make the symptoms worse and more … If the switch is stuck on this will cause the problem. Sure, he is not the one that has to reclaim, vacuum and recharge 134a. If I disconnect the pressure switch on dryer clutch stops. Okay, So I took my vehicle to a couple of hack shops, The A/C shop told me I had a ground problem so he sent me to a auto electric shop. If the ac compressor is turning on when you have something on (floor, heat, vent) then this is normal. Needless to say, I am not going to try another new one. In this video, I show you how to tell if a car's AC compressor clutch is engaging. Once you turn on the AC the center part of the compressor, the AC clutch should engage and start to rotate with the pulley. Vocational, Technical … Matuva - if you can get your control panel to shut off the A/C light with the button pressed ON, just by wiggling the blower switch, you have issues in that switch panel. I Had No Intentions Of Fixing But The 104 Degree Weather In Tx Is Starting To... Do I Need To Flush A/c System Before I Add Oil To It? When you turn on the heater it engages and dis-engages the air conditioner compressor in other words it clicks on and off and when it engages it makes the motor cut out bad and even when you turn on the air conditioner it makes the motor cut out. Not a whole lot was resolved. The center part on the pulley of the A/C compressor will not spin when you have the air conditioner off or if there is a problem. When I first turn the car on I can see the A/C clutch being engaged, but after the car runs for bit, then clutch disengages. when ac or defrost on clutch engages and motor has a serious load that effects idle... and ac stop blowing cold air - Ford 1996 F150 Regular Cab question When it is turned on it will start to spin. The cycling time is not right. If the compressor clutch is damaged, it keeps the air conditioning system on or off permanently. Wrong. The compressor clutch consists of a friction plate positioned adjacent to an electromagnetic coil. I have shot all wires in this system to the ECU and I have nothing grounding out. While A/C clutch is engaged, pressure gauge shows it to be on bottom side of green. If the compressor clutch does not engage, turn off the engine. It is an ominous sign when the clutch engages but the compressor does not spin. It does it when the AC is turned off and when the AC is on. If this shuts off the compressor, then we at least know which direction to look. Motor Vehicle Maintenance & Repair: My ac was not working so I installed a new ac pulley, clutch plate, and coil. when on preasure shot up to max and when off was at normal. When i first start the car, the AC engages every time and blows cold. The AC compressor switches on and off when idling, with a clicking noise. When it is off, the fanbelt just runs over the clutch and does no The AC is not "on". After a while it starts to engage for few seconds and than back off for about 10-15. From the looks of it, the climate control head is commanding the compressor on all the time. Roy, before I get a command center let me say that the compressor clutch would stay engaged all the time. Lol. 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