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It is responsible for controlling the blower motors fan speed. Blower Motor Resistor Test.
This is the blower motor resister which controls the fan.
Testing a blower motor resistor. Blower Motor Resistor Test. If you can hear the blower fan running but cant make it change its speed you probably have an issue with its resistor. Here are some tips on how to test a blower motor resistor.
Start by looking for the blower fan resistor. A repair manual can tell you where its location is in your vehicles make and model. In high speed the resistor is bypassed and power is fed to the motor directly from the switch.
Above is a typical blower resistor. Specifications and test procedures vary between different manufacturers. Place one lead of the Ohmmeter on terminal 1 of the resistor.
Place the other lead on terminal 2 and check against specifications. If this circuit is open showing infinity on the Ohmmeter the blower resistor must be replaced. How To Test The Blower Motor GM 43L 50L 57L.
Basics Of Troubleshooting The Blower Motor Resistor. As youre already aware your pickups heater control panel gives you the option of 4 different blower motor speeds. The reduction in blower fan speed is accomplished thru resistors.
Resistance Testing The Blower Motor Resistor To get our resistor block diagnostic on the way were gonna do a simple multimeter continuity test with the multimeter in Ohms mode. If the resistor block is defective youll get a no-continuity test result when testing across the indicated terminals. Resistance Testing The Blower Motor Resistor Were gonna test the continuity of the blower motor resistor with a multimeter in Ohms mode.
Youll need to remove the resistor block to test it and once removed youll be able to inspect it for any heatburn damage on it and its connector. Testing at the motor itself eliminates the possibility of confusion caused by complicated electronic blower controls found in Electronic Climate Control systems. Test for power at all the blower speeds by moving the blower speed switch through all positions.
A faulty resistor loses power at different positions on the switch. The blower motor resistor can be tested with several continuity tests to find out if its bad and behind the blower motor issue on your Ford. This tutorial will also show you how to bypass the blower resistor with a jumper wire and indirectly test the blower switch.
How to Test Vehicle ACHeat Blower motor. When your blower motor goes bad you will not get AC or Heat to blow inside of your vehicle you will also not be ab. To test a resistor or motor youll need to know the basics of electrical circuitry and have access to a multimeter and the proper electrical specifications for the involved circuits.
Testing whether theres power flowing to the blower in the first place is a good way to rule out a bad motor. You asked about testing the blower motor through the resistor pack. I would suggest grounding pin 3 and connecting a 12V source to pins 4 1 5 7 and 6 in sequential order.
If you want to test the blower motor directly disconnect it from the resistor pack power the red and ground the black leads to the blower motor. If you notice a heater core that is leaking fluid it may cause a blower motor resistor and blower motor to fail as the fluid will leak into the vehicle and onto these components. Upon visual inspection many times you can see areas of corrosion that have caused it to fail.
A 14-inch socket will be needed to remove the screws holding the cover. Locate the blower motor. The motor can be seen hanging down close to the passenger kick panel.
Just to the left of the blower motor an electrical connector connected to a flat 1-inch-by-2-inch plate can be seen. This is the blower motor resister which controls the fan. The blower resistor is connected in series with the blower fan.
This means that the current running through the blower motor and thus is speed is controlled by the resistor value. The user chooses a suitable fan speed by using a selector to connect one of the resistors in the blower resistor pack. The blower motor resistor is an electrical component that is a part of the vehicles heating and air conditioning system.
It is responsible for controlling the blower motors fan speed. This illustration shows a typical blower resistor specifications and test procedures vary between different manufacturers. Place one lead of the Ohmmeter on terminal 1 of the resistor.
Place the other lead on terminal 2 and check against specifications. If this circuit is open showing infinity on the Ohmmeter replace the blower resistor. Problems with a blower motor resistor are common in many cars.
The most common symptom of a failed blower motor resistor is when the heater fan only runs at the highest speed setting 4 or 5 and doesnt work at low speeds. In some cars a failed blower motor resistor can cause a heater fan to stop working completely. The blower motor resistor or final stage varies voltage to the blower motor to achieve the desired speed.
The blower motor is a DC electric motor driven by varying current supplied by the blower motor final stage unit. If your blower motor fails replace the blower and resistor together. You dont want to have to go back in if one fails later.