Even when the pressure should have made it turn off. More than likely you’ve got a problem with the unit. I will do you one better Ken. I Don't Hink This Car Has A Cabin Filter. Roy, before I get a command center let me say that the compressor clutch would stay engaged all the time. Low refrigerant charge will cause the compressor to run all the time as it won't be able to cool the coil to the required temp (freeze out threshold). My car has 167000 miles. I have a 2003 f250 6.0 Diesel. 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. I noticed my A/C compressor stays engaged when I turn the A/C on. A layer of grime on the fan blades can also slow it down, so again you may just need a good cleaning. It’s a relief to have some cooler weather, but one thing that may put a damper on your comfort level is the sound of your air conditioner running constantly when you know it shouldn’t be. At 35, the clutch will stay engaged. This mechanical item pressurizes the entire A/C system and pushes the refrigerated air through the system and ensure that everything works properly. Get your wiring diagrams out and work from the compressor back. Okay, do you mean if you have less than 20 lbs of pressure on the low side, the compressor is still engaged? The relay tells the magnetic clutch on the AC compressor to engage or disengage. Lol. I have replaced expansion valve, dryer, Freon. Thank you. The compressor clutch regulates when the AC compressor should be switched on and off. It is a thirty degree old school mechanical switch stuffed onto the EVAP core, a relay and a master kill switch for winter use. When this happens, the unit will keep running as it works harder. A system investigation can uncover leaks in the system. Fixed all the problems. So at 10 degrees outside temperature the pressure of the refrigerant is lower then the pressure needed to engage the pressure switch that allows the compressor to run. And now this. Start the engine and let it warm up. I Have Checked The Relay. From the looks of it, the climate control head is commanding the compressor on all the time. The clutch will engage regardless of the AC being on if the vent is set to defrost. Okay, Let me start over, I have had my vehicle to shops. Low side pipe that should be icy cold would always stay very very slightly cold. Talked to a friend who is a mechanic, he said there was air in the system. at the ac compressor it will have a pulley on it with a clutch that engages when the air conditioning is on. Just like the evaporator coils on the inside, the condenser coils on your outdoor unit also need to be cleaned, possibly even more so since they are exposed to the elements. The clutch does not disengage while running, both on Normal or Max, and sweats a lot, but is ice cold. If there wasn't enough in the system, it wouldn't even do that. AC compressor stays on all the time – Common causes Auto-climate control. That is the first good idea I have heard yet! If I disconnect the pressure switch on dryer clutch stops. If enough cool air escapes, the temperature in your space never reaches the set point and the system will keep running. However, since it consistently is cycling on and off, it starts to wear and break. If you do, then the system is likely low on refrigerant. Compressor runs for 4 second then off for 6 seconds then over & over. Ken, I removed the signal wire running from the relay back to the ECU. Blower motor and fan issues. I drive the car or let it idle for 1/2 hour twice a week. Check your thermostat to see if the actual temperature in the space is below the set point. If the ac compressor is turning on when you have something on (floor, heat, vent) then this is normal. 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. :-/. It’s also using way too much electricity and running up your electric bill. Replacing the faulty clutch assembly does not necessitate replacement of the complete AC compressor or evacuation and recharging of the air conditioning system. After a while it starts to engage for few seconds and than back off for about 10-15. if it engages and disengages it can be the clutch itself has gone bad, the ac clutch will also disengage if there is not enough freon in the ac system, will also engage and disengage if … The joints may not be sealed, or the insulation may be gone. The a/c constantly cycles. Your A/C compressor clutch is one of the most important parts of a vehicle’s air conditioning system. Did'nt fix it. The PCM disables the compressor clutch if the A/C pressure is more than 2957 kPa (429 psi). Brought into shop installed a new aftermarket cycling switch no results, installed a Ford update:-= new switch and wiring harness. That is why it disconnects when you remove the wires from the low pressure switch. The compressor has a magnetic clutch. If this shuts off the compressor, then we at least know which direction to look. Good luck. I am concerned that the compressor runs constantly when I turn on the AC, and does not cycle every 20-30 seconds as I recall it used to, though the temperature here hasn't dropped below 85 degrees since the repair. If you don’t have enough refrigerant in the system, probably due to a leak in the coils, your unit can’t cool the space. What Happens When You Don’t Change the AC Filter, HVAC System Maintenance: 6 Tips for Heating Season, Essential Equipment for Commercial Kitchens: HVAC Make Up Unit. If your outside condensing unit keeps losing power and tripping the circuit, … The underdash multiplex unit in fusebox went bad and took the ac out, dome light, power door locks,etc. You can always test the clutch by disconnecting it and seeing if the cool air stops. Is your AC running all the time without shutting off, or cycling on and off continuously? The electrical auto guy says it is a thermostatic meter. Since the clutch engages, there is enough refrigerant in the system (pressure) for the clutch to engage. Automotive air conditioning system uses an electromagnetic clutch mechanism that engages the compressor to turn the AC unit. But I did when I put the used fusebox in. How to keep your AC working year round The AC lines are ice cold and it still cools really well but I don't dare use it till the clutch cycles correctly. A good cleaning using professional products and tools will take care of this problem. Jump to Latest Follow 1 - 5 of 5 Posts. The clutch will be enabled after the pressure decreases to less than 1578 kPa (229 psi). If it is, there’s a good chance that the thermostat may need replacing. For better air flow, use a filter with a lower MERV value. A belt drive attached to the engine spins constantly, providing energy for the AC compressor. Clogged air filter. And don’t forget about the wear and tear on your air conditioner from all that unnecessary work. Frozen evaporator coil. A defective compressor clutch can be replaced, but it is generally recommended to replace the entire compressor to save time and additional costs. The only way to stop it is to disconnect it at the top of the compressor with the little 2 wire plug. While A/C clutch is engaged, pressure gauge shows it to be on bottom side of green. I have this exact issue haunting me right now. IAQ and Mold in NYC Buildings: Are Kids at Risk? Faulty thermostat. What’s more, neglecting this task can be costing you in many ways that you haven’t considered. GLYN, if you get any further along, please post it here. If your unit is blowing warm air from the supply vents in addition to running constantly, it may have frozen up. A/C clutch engaged all the time. It appears I have a ground problem, that was the answer from the A/C shop. As for the A/C running at +10F outside temperature. Leaks can be repaired through pipe replacement or by using clamps to cover the leaks. 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. Compressor, condenser, evaporator, expansion valve, dryer, triple pressure switch, relays, thermal control amp, control head and even swapped the ECU! If the cold air does not stop, then I'd say the clutch is stuck. To utilize the AC on your car on demand, the clutch compressor is activated. Please confirm this so we can continue. The colder the day is the faster it will cycle off. He took to shop and they replaced thermosensor on compressor. Compressor clutch disengaged and both rad fans stopped running. Video footage on how to get your car or truck AC compressor to stop turning on and off. I am really starting to give the new pressure switch the stink eye. Without enough air flowing over the coils, the system can’t remove humidity and cool the air to the set temperature, so it keeps running when it shouldn’t. This is unlikely because the refrigerant pressure is relevant to temperature. Yes, trial and error we will find the problem. Leaky ducts. The cycling time is not right. Pressure on low side ranges from 35-45 psi. The mechanic added 3oz of oil and 20oz of 134a. 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. The compressor runs constantly from the time the engine starts. Turn the air conditioner completely off, and. If your blower motor is not producing enough air for your system, or the fan is running at a low speed, that can cause the system to lose enough efficiency to make it run too much. The belt turns a rotor, which has a friction plate attached to it. Fault Explanation: :Compressor clutch: open circuit or short circuit to positive I plan on unplugging compressor and testing voltage going to it then applying 12v directly to compressor clutch. Incorrectly sized unit. Adjusting the fan speed can solve the problem. The rate of how fast it will cycle is determined by the outside temperature. The flow of air can be impeded by dirt and debris from the air, but also from accumulated leaves or even animal or insect nests. Dirty or blocked condenser. When you turn on the AC a signal is sent to a relay located in the main fuse box in the engine compartment (which Jeep calls the Power Control Module or PCM). It’s possible that your unit is no longer adequate for the needs of your space. Been that way for years. When the AC is off, the wheel spins freely. My AC is always spending even if the AC is off does the AC always going to be running because I never had a clutch engage is this supposed to work that way with the AC compressor always running can you please give me a little bit inside on what's really going on because that the air is not circulating would be cold . A defective AC compressor clutch assembly can cause excessive noise or vibration when the air conditioning is on. Low 35 are so, high going up to 250. Don’t “Let it Go!”, Commercial Refrigeration Service & Repair, AC Troubleshooting: 10 Common Causes of a Constantly Running System, Calculating the Hidden Costs of Poor HVAC Maintenance, COVID-19 & Your HVAC System: Your Questions Answered. Seems to me right after I rebuilt the entire AC system, I had rapid clutch cycling. Most of the time the clutch fails and locks to the compressor housing causing the compressor to not turn. Improved parts are available. It has to drop below 20 to disengage the clutch. Here are some of the most common causes of this problem to help you do a little AC troubleshooting: Many of these issues can be taken care of, and even prevented entirely, with regular maintenance of your equipment. Who knows, maybe the new ones are not wired correctly? Clogged air filter. Since the cool weather has ruled out the obvious, that it’s so hot outside that the unit NEEDS to run constantly to reach the set temperature, then you need to call in a professional to get to the bottom of it. Eighty degrees outside (Texas). If your thermostat is not working correctly, the unit doesn’t know to turn off even when the temperature is reached. I pulled the rear hvac fuse and the heat/ac fuse and the compressor stayed running. 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