Monday, December 12, 2011

How to Test And Replace Blower motor On car?

The blower motor is a small electric motor and fan assembly that's RPM-regulated by a slide control rheostat that provides fan speeds from low to high. It powers the blower fan or squirrel cage to force air through the heater core or A/C evaporator core and into the passenger compartment.
First inspect the blower motor.
If there is no air coming from your vents when your car is stopped, the most common problem is a failed blower motor or motor circuit. If air comes from the vents while driving, the blower motor is inoperative for some reason. Perform the following test on the blower motor circuit.

WARNING:-------------- Do not use a test light on blower motors that are on automatic climate control systems unless directed to do so by the service manual. The motor may not be considered electronic, but its controls will be, and most do not have a resistor block for motor speed control. Damage to the circuit can result if test procedures are violated.
As usual, check the fuse first. If it is good, locate the feed wire to the blower motor and check for voltage with a multimeter or voltmeter. With the meter connected from the feed to a good ground, turn the ignition switch to RUN and place the blower control switch in each position. If there is voltage in one or more speeds but not on all, check the service manual to locate any resistors. Most vehicles have a resistor block between the switch and motor. The resistor block controls the amount of voltage reaching the motor, thus adjusting its speed. At the resistor block connection, use a wiring diagram to determine which of the three or four wires are coming from the switch. Test for voltage in each switch position. Voltage on each conductor indicates that the resistor block is open. Voltage on some or none of them indicates there is a problem within the switch. The switch and block are not repairable and must be replaced individually.
No voltage at the resistor block output or at the motor indicates an open in the circuit. Some manufacturers like Ford use a thermal limiter in the resistor block. The limiter acts like a circuit breaker and opens because of excessive current or heat. The thermal limiter is usually part of the resistor block and the block has to be replaced.
If there is voltage at the motor in all speeds, check the motor's ground before replacing it. Connect the meter between the feed wire and the ground wire at the motor. Move the blower switch and ignition to ON. A voltage reading indicates that the power and ground are good and the motor must be replaced. No voltage at this point indicates the motor's ground is bad. Repair the ground wire or connection.

Follow this procedure to Test its Components.The details will diagrams is as follows :----

As usual, check the fuse first. if it is good, locate the feed wire to the blower motor and check for voltage with a multimeter or voltmeter. with the meter connected from the feed to a good ground, turn the ignition switch to run and place the blower control switch in each position.
This motor has a positive power even though the ignition key is on and the blower switch is off. The circuit uses a grounding switch that is typical of those found in electronic circuits.
If there is voltage in one or more speeds but not on all, check the service manual to locate any resistors. Most vehicles have a resistor block between the switch and motor. The resistor block controls the amount of voltage reaching the motor, thus adjusting its speed.
Typical location of a resister for manual heating and A/C systems.
At the resistor block connection, use a wiring diagram to determine which of the three or four wires are coming from the switch. Test for voltage in each switch position. Voltage on each conductor indicates that the resistor block is open. Voltage on some or none of them indicates there is a problem within the switch. The switch and block are not repairable and must be replaced individually.
To Replace Blower motor,it all depends on what brand and car model you have.But its not very hard.
Check the procedure mentioned below,for basic blower motor removal:-----]

  • Disconnect the negative battery cable.
  • Disconnect the blower motor lead connector from the wiring harness connector.
  • Remove the blower motor cooling tube from the blower motor.
  • Remove the four retaining screws.
  • Turn the motor and the wheel assembly slightly to the right so that the bottom edge of the mounting plate follows the contour of the wheel well splash panel.
  • Lift up on the blower and remove it from the blower housing.
  • Installation the new blower motor by reversing the removal steps.
  • Connect the negative battery cable.

This procedure will help you to inspect,test and replace cars blower motor.
---------------
If you need dis-assembly or replacement instructions for any other auto/car part, or you want to ask question related to your car/truck jeep problem then please leave the comment with your details, so I can provide you the required instructions and solutions.

For Instructions regarding All types of car heater problem repairs.Check the list below:---

All types of Car heater Problem troubleshooting?


Blower only blows warm air ?

http://schematicsdiagram.blogspot.com/2011/11/blower-only-blows-warm-air.html

AC cool air enters only the passenger compartment even with the heat control turn all the way?

http://howtobyme.blogspot.com/2011/11/ac-cool-air-enters-only-passenger.html

Saturn Car Blower motor Only works on High?

http://howtobyme.blogspot.com/2011/11/saturn-car-blower-motor-only-works-on.html

No hot air from defrost vents?

http://howtobyme.blogspot.com/2011/12/no-hot-air-from-defrost-vents.html

Radiator replaced but still Car is over heating?

http://howtobyme.blogspot.com/2011/12/radiator-replaced-but-still-car-is-over.html

Ford ranger heater blows cold air?

http://schematicsdiagram.blogspot.com/2011/12/ford-ranger-heater-blows-cold-air.html

Audi A4 blower motor blows Warm Air?

http://howtobyme.blogspot.com/2011/12/audi-a4-blower-motor-blows-warm-air.html

Heater stuck on defrost?

http://howtobyme.blogspot.com/2011/12/heater-stuck-on-defrost.html

Where is Blower motor resistor located on 2006 Ford F 250?

http://schematicsdiagram.blogspot.com/2011/12/where-is-blower-motor-resistor-located.html

Dodge Caravan AC Heater Control only works on high mode?

http://schematicsdiagram.blogspot.com/2011/12/dodge-caravan-ac-heater-control-only.html

Honda Civic Blower Motor Only works on high mode?

http://schematicsdiagram.blogspot.com/2011/12/honda-civic-blower-motor-only-works-on.html


1 comment:

  1. This is very hectic job to check and replace the motor,i found this blog quit useful,A very easy way to prolong the life of your Car batteriesis to keep it clean. Most of the time you
    can simply use a soft rag to wipe it down, but if it has become grimy you may need to use a mild
    detergent.

    ReplyDelete