Does engine coolant affect ac performance?

High coolant temperature affects A/C performance.

The engine cooling system has an indirect influence on the performance of the A/C system. High under hood temperatures can be the cause of poor A/C output. 

Always verify correct operation of:

  • Engine coolant level and condition
  • Low coolant will cause high under hood temperatures
  • Does the cooling system need flushing?
  • Has the vehicle followed the manufacturer’s service intervals for flushing?
  • Does it have the correct coolant in it?

  • Thermostat
  • Has the thermostat ever been replaced?
  • Is it stuck, not closing or opening all the way?

  • Radiator
  • Is the radiator plugged internally or externally?
  • Are there any signs of leaks?

  • Water pump
  • Is the mechanical pump circulating the coolant properly?
  • Are electric pumps working properly?
  • Should it be replaced when servicing the timing belt?
  • Belts,tensioners,and pulleys
  • Check for proper belt tension and verify the belt is not slipping
  • Check tensioner alignment

Why did my car AC stop blowing air ?

My car A/C stop blowing air from the vents.

Common reasons for this to happen:

  • A/C blower motor circuit blown fuse
  • Bad blower motor resistor
  • Blower motor shorted
  • Bad blower motor control switch
  • Poor ground connection
  • Poor blower motor connections

Ram air flowing through the evaporator does not provide enough air flow inside the vehicle for cooling purposes. So, a blower is used to force the air along. An electric motor spins a fan, forcing the air into ducts, which direct it to the particular vent selected by the operator.

If the blower motor gets full voltage, it will run at high speed, but that is not always desirable. Therefore resistors are used to cut the speed down. The fan switch directs the current flow through one or more resistors to achieve the slow and medium speeds.

Why did my car AC suddenly stop working?

The most common causes of broken air conditioning are:

Leaks, compressor issues, electrical / electronic faults.

Compressor and electrical / electronic faults.

Inputs that may affect A/C clutch operation include (but are not limited to):

  1. A/C system pressure
  2. Engine speed
  3. Throttle position
  4. Engine coolant temperature
  5. Intake air temperature
  6. Power steering pressure

If these sensor and switch values are either above or below the programmed operating range, the compressor clutch may not engage

Depending on the vehicle, additional items that may affect compressor operation could include:

  1. A/C mode switch/actuator
  2. Body control module
  3. High and low pressure cut-out switches
  4. Compressor clutch cycling switch
  5. Refrigerant pressure transducer

Refrigerant leaks .

There are two types of refrigerant leaks in the automotive air conditioning system: Active leaks and Passive leaks.

  1. The active refrigerant leak is a continuous leak. It doesn’t matter if the engine or ac system in your car is off or on hot or cold the refrigerant continuously leaks out
  2. The passive refrigerant leak is a type of leak the intermittently occurs. They are really hard to find, because technicians should recreate the same conditions of pressure, temperature or vibration for the leak to happen.

When should I change my AC filter drier?

Receiver-drier location.

The receiver drier is a storage tank for the liquid refrigerant from the condenser. It also contains a bag of desiccant.

The purpose of the desiccant is to absorb any moisture that might enter the system during assembly or service. The receiver drier is often neglected when the air conditioning system is serviced or repaired.Failure to replace it can lead to poor system performance or replacement part failure.

When should I change my AC filter drier?

It is recommended that the receiver drier and /or its desiccant be changed whenever a component is replaced, the system has lost the refrigerant charge, or the system has been open to the atmosphere for any length of time.

AC receiver drier refrigerant flow restriction.

If the receiver-drier outlet is colder than the inlet, this unit is restricted and should be changed to restore efficient and proper system operation.

How much refrigerant does a car need?

What happens when refrigerant is low?

A low refrigerant charge may cause faster than normal clutch cycling without frosting of any components.

 AC system overcharged.

A flooded evaporator would cause elevated low-side pressures and frost to develop on the suction line.

AC system restriction.

A restricted accumulator would likely result in a noticeable temperature drop.

Why does car stall when AC is on?

Why does my car hesitate when AC is on?

A vehicle that is stopped stalls when the steering wheel is turned to full lock only when the air conditioning is on.

The power steering pressure switch signals the computer to increase the engine idle speed during parking-type maneuvers. If the vehicle has a bad power steering pressure switch, the engine could stall at idle when the steering is moved to the full lock position. This is due to increased load on the engine from the power steering pump.

Symptoms of a Bad or Failing AC Clutch Cycling Switch.

A/C cycling clutch systems.

In cycling clutch systems with a fixed orifice tube, a low-pressure or cycling clutch switch is placed in series with the compressor clutch circuit so it can turn the clutch on or off.

Air conditioning system protection devices.

The AC cycling switch de-energizes the clutch and stops the compressor if the pressure gets below a certain level (usually about 20-25 psi) .It closes and turns on the compressor at about 40-47 psi.

Dirty evaporator core.

Air flow restriction.

When the fins and air passages of an evaporator are clogged with dirt, air will have a difficult time passing through the evaporator. Since the principles of air conditioning require the heated air around the evaporator to lose heat, a vehicle with a clogged evaporator will have poor A/C performance.

Evaporator core maintenance.

The evaporator core should be removed from the case to properly clean it. Airborne debris, such as leaves, lint, hair, and other contaminants, enters the evaporator case and clings to the wet evaporator core.

The A/C drainage.

The drain is for the purpose of removing the condensation that forms as a result of humidity being removed from the intake air. It is nearly impossible to adequately clean an evaporator core without first removing it from the case.