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To test the blower motor resistor, unplug the resistor connector. Each blower motor switch input terminal on the resistor must have continuity to the resistor output terminal, which is connected to the circuit going to the blower motor. If the blower motor resistor continuity does not check OK, replace the faulty resistor.You need a multimeter to test the resistor block and there should be continuity between all terminals.
If you are saying that the blower motor only works on the high speed setting, then the Blower Motor Resistor is defective and needs replacing.
Short in the circuit somewhere. Try unplugging the blower motor, closing the circuit with a test lead or test light, and seeing if it blows then. If not, the problem would seem to be in the blower motor itself.
You can unplug the blower motor and run a jumper wire to test the blower motor. If it is grounded through the plug you'll have to run a ground wire to it also. Blower Motor tested good. The Problem was the Blower Motor Controller which was located on the firewall just below the Heater Hoses. Thanks for responses to question.
Remove and test with an ohmmeter Explain how to test with an ohmmeter?
Blower motor is usually behind the dash on the passenger side. Try removing the glove compartment to access it. If the blower isn't working, it could also be the resistor block (more likely to burn out than the motor itself). One blown resistor could keep the blower from blowing at all. Check that first (look for scorching and test with a test light). It's a pretty easy replacement and if the blower is not getting current replacing the motor won't do you any good.
You can test your heater blower motor by connecting a ground wire to the ground. Connect a power wire, from the battery to the positive post. If the blower motor turns it is working, and if it does not it is bad.
Check the fuses.If not the fuse, test the resistor down by the blower motor.
Yes, bad blower motor but could be just a bad resistor (blown fuse). Maybe both need to be replaced. You can test the motor by jumping it.
The most conclusive test of a blower motor is to run a wire from the battery directly to the motor, being careful not to ground the wire out anywhere by accident. If the motor will not run when wired directly to the battery, it is probably bad.
Test the resistor bank before getting into anything else. These are the speeed controls for the blower motor.
Try wiggling the electrical connector at the blower resistor. If wiggling this connector makes the blower go on and off, turn everything off and replace the connector before anything catches fire and burns the truck down.Next, when the blower is not working, set the fan speed to hi and try gently tapping the blower with a hammer. It that makes the blower come on the blower motor is bad and should be replaced. Also, use a test light or voltmeter to check for voltage across the two wires at the blower motor when it won't work. If voltage is present but motor won't work, motor is bad.