Description: I recharged refrigerant but why my ac making humming noise top 6 reason, lets discuss why, Most owner frustrating AC unit humming noise issue, you have recharged, and thinking now its ice cold air coming, but instead you are greeted warm air or very less air flow at all, also AC making Humming noise, this guide will walk you through the most common air conditioning problem and help you to figure out why your ac is not getting cold, even after recharge.
AC Gas recharge, but still not cold (HOME AND CAR)
Most of the time if our AC not cooling or less cooling we are thinking ac refrigerant quantity is very less that is the reason ac less cooling and we are go to the repair shop and filling ac gas and check cooling is ok, but after few days you are facing same issue, that means your ac system have some leakage any of the component may be evaporator or, any hose pipes either condenser.
Some time your ac system dont have any leakage but have some blockage, means every ac system have an expansion valve this parts lequid refrigerant convert to the vapour refrigerant and flowing to the evaporator side very small passage, if this small passage have some blockage, your ac pressure goes high and ac not cooling enough and very less cooling.
Another reason is your vehicle ac compressor magnetic clutch is malfunction and some time not engage even power supply is coming, either ac compessor have some pressure variation and affect on ac that is a reason behind it ac less cooling or ac not cooling while driving and stop at parking and while stop in ideal condition also.
This is the very big concern you will may be face if your AC have example 550ml ac gas quantity standard and you will put 700ml its not good for your AC air conditioning system its damage your ac parts even leakage occured, so first check in your AC unit there mention every brand what is the specific quantity you can recharge.
AC not getting cold – general cause (HOME AND CAR)
Clogged cabin filter: If your AC have not proper service, means according to the service cabin filter not replace or cleaning ac vent not coming cold air because of blockage cabin filter and also you feel bad smell inside your cabin compartment, should be replace ac filter in every service according to the service standard may be every service is depend on brand to brand.
Failing cooling fans: Some time you realise ac very less cooling either you seen in DIGITAL DISPLAY overheat signal coming also, you can check easily check this, you will open your car hood start the vehicle and on the ac switch and check condenser fan is working or not, if not working you can check this fan motor fuse if blown change it and check fan working good either some time fan also need to be reaplace and solve this problem.
Bad AC pressure switch: If your car’s AC pressure switch wiring is damaged or ac pressure switch has an issue, in case the AC compressor is not working also even if no leakage clutch is engaged, make sure your car pressure switch side is ok. This switch is mostly located on the high-pressure hose.
Electrical issue: blown fuse/ wiring. Very rare case wiring issue, but sometimes the AC compressor magnetic clutch relay or fuse has some issue you feel in the fuse box, while on ac relay, there is no clicking sound, which means the relay is not working and should be replaced.
AC is making a Humming noise and not cooling
Refrigerant leak, If you feel inside sit on car and ac switch on and this hissing noise will come means your ca ac system have some leakage, mostly evaporator leakage coming about this concern either expansion valve o rings, becuse cold and hot variation expansion valve rubber band o ring will expand and hard also, there have more chance to leakage this refrigerant slowly and making hissing noise if you have a ultraviolet torch you can seen this refrigerant where is actual leakage, some time if you open your car ac filter there have some smell and colour also like green colour.
sometimes ac have no leakage but same Humming noise will come that means most car owner dont know how much ac gas quantity should be fill inside car he will buy a can type ac refrigerant and fill it may be this is low either this high quantity, also this fillng time some air going inside the system and bubble occured and air mix with ac refrigerant and making hissing noise while ac is on, so conclusion is you should be top up proper quantity and top up refrigerant with standard ac gas filling machine.
Car AC not cooling at all
No air blowing, some time after ac switch on no air came out through the vent, because blower have some issue either blower fuse or ressister have some malfunction you can check blower fuse on the fuse box located inside car like glove box side either steerinh down side if blown fuse need to change if still not work blower have some problem, some time blower have work on high speed only that time mostly ressister damaged need to replace that time resistor with blower motor
Dead AC compressor. Most of the time, ac compressor is fully dead, everything is ok, but the compressor does not work. At that time compressor clutch inside the resistor is broken, and the clutch has no power to engage or pull back. Better to replace the full set of the compressor clutch assembly.
The faulty ac switch, sometimes the ac switch does not work due to an electrical malfunction internal circuit has a problem sending the signal to the ECU on the ac; at that time ac switch assembly needs to be replaced because there have a very small circuit; it’s not safe to repair.
The auto AC not blowing cold air
System may not be cycling properly: sometime ac system refrigerant cycle not working properly due to some blockage in this system mainly low pressure and high pressure pipe making with aluminum and rubber item for hard and flexible easy to bend and fixing, vehicle are using more times may be 200k after this pipe rubber item inside touch to refrigerant little little worn out and mix with refrigerant cycle and block to compressor or any small passage that time ac pressure going high and inside cabin ac not blowing cold air through the vent.
Another thing is auto AC while on its automatic temperature control and blower speed control, also it takes data from the outside ambient temperature sensor and the inside intake temperature sensor, and combined generates a standard temperature, according to the how many people inside the cabin.
Faulty door actuator: some automatic air conditioning vehicle ac door actuator have some issue, like you set cooling temperature 18 in celcius either 60 in fahrenheit but ac vent not blow cold air because your vehicle door actuator inside fix to the heater unit there not switch to change this actuator open on heat mode or slightly open on cold mode, in that situation you feel driver and passenger side cooling air flow is different, means 1 side have some issue need to replace this door actuator.
Moisture or air trapped in the system during recharge of ac gas, I already discussed previously that if you recharge AC gas except genuine AC machine, most possible chance inside air trapped or came in moisture while recharge if coming moisture in system, it can mix with the refrigerant and chance to damaged ac system component.
My car AC not working, what should I check
Step-by-step diagnosis checklist
1) Check the fuse box for any fuse’s blown fuses in the AC system, like the compressor clutch fuse.
2) Inspect refrigerant pressure, high pressure, and low pressure. High pressure standard is 140 to 210 psi, and low pressure is 25 to 35 psi is standard and this range is small sedan to all kinds of cars.
3) Check for leakage if you have a UV dye while you recharge AC refrigerant, as an alternative to compressor oil, you can use it for visible leakage.
4) Check the cabin filter if dirty; clean it properly, located most of the vehicle’s passenger side glove box.
5) You can check once in your car, open the hood, and see any wiring cut or damage, before driving the vehicle.
AC is not cooling in my car as per brand brand-specific issue
Sometimes few brands have a setting on the AC control panel to enhance cooling efficiency people don’t know how to use and they will raise a complaint to the dealer My new vehicle, why is the AC not cooling properly.
Truck AC not working
Truck is common use on off road and heavy duty purpose so this types of vehicle mostly found on condenser damage or hit mark that is the reason behind truck ac not working or very less cooling because after hit front side or some time road some item hit on the front condenser or radiator while driving in expressway, after hit condenser line ac refrigerant fully release and ac not cooling, if this problem will come should be replace condensor.the the the
Truck requires a heavy quantity of refrigerant, mostly 2000ml or above, so make sure while topping up the refrigerant, recharge the proper quantity, or you will face the same concern.
MY car ac is not blowing air
Very rare but sometimes the AC control unit comes in a few models If this one fails failure your car’s AC system shuts down even ac control panel light will not come on, you press but not switch on AC, maybe be wire is loose, the connection is either cut or the control unit malfunctions.
Even sometimes only programming is required, depending on this model, a bulletin coming from a brand, if it has a bulletin, in that case, only needs to be programmed. The car is blowing air and cooling again.
FAQ
Q)WHY IS MY CAR AC NOT COLD AFTER RECHARGE?
A) The main cause is leakage in the AC system, a faulty compressor, or system blockage.
Q) CAN OVERCHARGING THE AC SYSTEM CAUSE NOT COOL?
A) Yes, too much refrigerant can reduce performance and even damage ac component.
Q)WHAT DOES A HUMMING SOUND FROM AC MEAN?
A) It often means leakage in this system, mostly the evaporator, and an imbalance in refrigerant quantity.
Q) How to fix car AC not blowing cold air?
A) You can check your car’s condenser may be more dust particles that may be blocking the condenser fins, you can clean by an air and water spray, making sure you spray air or water vertically, either damage the condenser fins, and after on ac and check becomes cold your car’s AC becomes cold.
Q) CAR AC NOT COLD ENOUGH IN HOT WEATHER?
A) The best way to cool your car’s AC before summer you can check the ac refrigerant quantity and condenser cleaning If little less ac refrigerant, you can do only recovery and recharge, and check once any leakage is there or the cabin filter condition if filter little dirt,y do clean by air only.
