How to Troubleshoot a Blower Fan Non Working
by Troy Lambert
Integer Multimeter image by TekinT from Fotolia.com
To determine the cause of a cetacean fan failure, isolate the motor, and perform some basic electrical tests. Bring broad knowledge of electrical energy and specific knowledge of the use of electrical testing equipment. A wiring plot for the taxonomic group fomite is also helpful. Keep an eye o safety precautions while working with electricity.
Follow the Power
Step 1
Check fuses first. Fuse nonstarter often causes component failure. Replace fuse if blown; if not, proceed to Step 2.
Step 2
Check for power at the centrifugal itself. Using a test light or a multimeter set happening volts, unplug the blower motor. Keeping the black confidential information on a good ground, ordinarily a bolt happening the engine block, and the blower switch turned happening, use the blood-red lead to probe the plug that usually attaches to the cetacean mammal motor. The meter should show between 9 and 11 volts or the test light will light up. If the voltage is right or the mental testing sparkle illuminates, go to Step 3. If not, cut to Step 4.
Step 3
Test the connectedness to the cetacean motor. Take two jump shot leads, one pitch blackness and one red. Connect the black lead to a flat coat and so to the blower motor assembly. Connect the red lead to a tycoo source and then to the leads on the motor side of the disconnected connector. If the motor turns, the connector is bad. Repair the connector. If the motor still does non turn, the motor is rotten. Supersede the motor.
Test the switch. Plug the connexion back in to the blower motor, and so trace the wire rein in back to the connector nighest to the blower efferent switch, usually placed low-level the dash. Disconnect the connector and set the multimeter to ohms. Place one lead on unrivalled prong of the connector and the other Pb on the power in prong of the connector, fetching care that they do not trace each different. If you move around the shift along, you should get a reading between .01 and .03 ohms. A slightly high reading is acceptable because switches vary in electrical resistance. If you get no reading on any of the switch settings, the switch is bad. Replace information technology.
Going Deeper
Step 1
Trial run to date if the trade is getting major power from the battery. Going the switch disconnected, switch the multimeter to volts again, or use a test light. Earthing the black lead as before, use the red lead to investigation the connective. Usually a sick or red conducting wire will be the calefacient, or business leader, wire. Consult the wiring diagram for the specific fomite if the wire colour is unknown. If the meter shows the correct potential dro, or the test light illuminates, the switch is getting power, skip to Stone's throw 3. If it does non, proceed to Step 2.
Step 2
Look for a break in the wiring harness if the test light does non light, or the beat shows no value, there is a break in the wiring harness between the substitution and the battery. Follow the wiring harness, checking the hot cable for voltage at every connection, until you find the break. Repair the soften.
Look to a break in the wiring 'tween the tack and the fan if the meter shows voltage OR the light illuminates and you have tested the switch and efferent. Follow the wiring harness as carefully equally possible betwixt these two locations, looking burned out spots Beaver State breaks in the wire. When the break is situated, stamping ground or supervene upon the wiring harness.
References
- "Haynes Techbook, Automotive Electrical Hand-operated"; H. Haynes; 1990
Tips
- If you find neither the efferent nor the switch faulty, you may want to leave the deeper troubleshooting to a professional.
Things You'll Need
- Multimeter
- Pinafore leads
- Test palish
Warnings
- Mind of shock hazards implicit in employed with electrical systems, and use caution.
Writer Bio
Based in North Idaho, Troy Lambert has been writing how-to pieces and historical articles for magazines such as "Woodwork" and "Outdoor Idaho" since 1994. Leonard Constant Lambert is as wel a novelist and has a diverse discipline and philosophical education. He holds a technical certificate from the Cycle Mechanics Institute in Phoenix.
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