HEAT RESIST AND DON ’ T LOSE YOUR COOL
VITAL NEWS gathers essential information about interior blowers and heater resistors from Heating , Ventilation and Air Conditioning ( HVAC ) specialists to avoid any blowouts this winter .
On top of driver comfort , interior blowers and heater resistors work in tandem with the rest of the HVAC system to assist driver safety . They regulate temperatures to keep the driver alert and prevent windscreen fogging .
Due to their frequency of use , interior blowers and heater resistors are often high-demand components . As they are interlinked , many technicians tend to misdiagnose problems with these parts . FPS suppliers of HVAC components – Nissens , Valeo , Hella , febi , DENSO and Bosch , have come together to clear the air about these components .
INTERIOR BLOWERS
CHARACTERISTICS
200
INTERIOR BLOWERS
HEATER RESISTORS
CHARACTERISTICS
100
HEATER RESISTORS
Located in the HVAC module between the cabin air filter and evaporator or heater radiator , interior blowers function to continually draw air from the outside or maintain air re-circulation inside the passenger cabin . It takes cold air from the evaporator or warm air from the heater radiator .
Interior blowers are made up of an electrical motor and many plastic parts . Due to the temperature variances , it is important that the plastic elements are constructed using good quality materials for durability .
Carbon brushes and copper wirings within the electrical motor must be able to withstand electrical peaks during normal working conditions . High electrical loads can cause low-quality carbon brushes to melt and warp the plastic covers , leading to interior blower failure .
Heater resistors enable the heater blower motor to change the speed of the fan . While it works in tandem with the interior blower , it is often overlooked during inspection when a vehicle owner encounters a HVAC problem .
Without a resistor , the speed of the airflow from the blower motor cannot be changed or will completely fail to work . A faulty resistor can lead to an electrical drain , causing a flat battery as the fan will only work at the highest setting .
TROUBLESHOOTING
> PROBLEM : Blower does not start regardless of speed selected . TRY : Checking if the fuse is blown and if so , replace it with a new one that is the same voltage . Alternatively , check if the connector to the blower is mounted correctly and make sure that the blower wheel is clean , without obstruction . Also , check if the generator is producing more voltage than appropriate for the blower .
> PROBLEM : Blower only starts in one or some of the selected speeds . TRY : Checking if the heater resistors are defective . In the event that the heater resistor is integrated into the blower , the entire unit must be replaced .
> PROBLEM : Blower is very loud and sometimes squeaky or blower runs slowly or at an inconsistent speed . TRY : Replacing the interior blower entirely . There is a mechanical defect with the carbon brush elements .
TROUBLESHOOTING
When a blower only operates out of two speeds instead of four , or when the blower completely ceases to function ( i . e . no air from vents ), there could be something wrong with the heater resistor . Faulty heater resistors need to be replaced swiftly to avoid further damage to the rest of the HVAC system following a thorough inspection .
FPS has one of the largest interior blower and heater resistor ranges available same / next-day within the independent aftermarket . Contact your local FPS representative for more information .
8 HEATING , VENTILATION AND AIR CONDITIONING VITAL NEWS ISSUE 44