13
Jul
Resistance Testing The Blower Motor Resistor 1 2 Were gonna test the continuity of the blower motor resistor with a multimeter in Ohms mode. The heater blower motor is located behind the glove compartment of your vehicle.
Alright these are the test steps.
Testing a blower motor. Clean out any debris from the motor. Clean the blower motor with an electrical-parts cleaner. Check that the blower wheel spins freely and all the other parts are operating properly.
If a part isnt working properly clean and oil it and test it again sources. Testing the blower motor of your home HVAC system If debris is not the problem use your multimeter to check for voltage in the contacts motor. The resistance ohms of the windings should be tested.
If its a zero reading then this indicates that your winding has a shortage. Applying Battery Power And Ground To The Blower Motor. Testing the blower motor is as simple as applying battery power and Ground to the blower motor terminals.
Depending on the exact location of the blower motor on your specific 38 liter equipped GM vehicle you can test it on the car or you may have to remove it for ease of access. The capacitors on most of residential blower motors are very small so technicians tend to overlook them. Using a capacitor tester to test the capacitor.
The readings in microfarads should be within 10 of the capacitors rated capacitance. You should discharge the capacitor before handling it. Testing The Amperage Draw Of The Blower Motor The first thing were gonna do is to test the blower motors amperage draw.
We need to see if the blower motor is drawing a high amount of current above 40 Amps because if it is then its defective. 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. The top cause of fan motor breakdowns is a bad run capacitor. Always visually check the capacitor before you start testing because ruptured capacitors and capacitors with dents or any other types of deformities are obviously broken and you need to replace them as soon as possible.
Blower Motor Resistor Testing An AC blower motor resistor uses resistance to control the speed of the blower motor. Many blower resistors control current to the blower motor in all speeds except high. In high speed the resistor is bypassed and power is fed to the motor directly from the switch.
Alright these are the test steps. Disconnect the blower motor from its 2-wire electrical connector. Youll notice that the 2 wires of the engine wiring harness connector that connects to the blower motor are an orange with a black stripe ORGBLK wire and a black BLK wire.
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. Resistance Testing The Blower Motor Resistor 1 2 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. The heater blower motor is located behind the glove compartment of your vehicle. Disconnect the negative and positive power supply.
The black wire is usually the negative Using a multimeter set on the Ohm scale use the positive lead and test the black wire. Remove the wire connector that can be seen at the blower motor itself. Test this connector for power.
If there is power at this connector the blower motor is at fault and needs to be replaced. If there no power is found the blower motor resister is the culprit and needs to be replaced. 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. HVAC blower fan testing diagnostic questions answers.
Reader questions responses help diagnose trouble with the blower fan or air handler fan used in both air conditioning and heating systems. This article series discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. We also discuss convector unit fans and we suggest diagnostic.