Auto Repair Help

by Lance Wright

The blower motor is used to distribute aiBlower Motorr flow through the HVAC module and into the vehicle. The blower motor system consists of an electric motor, blower fan, blower relay, blower motor resistor and the blower motor wiring and switch. Refer to the appropriate auto repair book to get the schematics of the blower motor and it’s connections.

Operation of the blower motor is controlled by a switch mounted in the HVAC control panel. The switch has multiple speed settings that control voltage supplied to the blower motor. Low and medium speeds are made possible by causing current to flow through the blower motor resistor assembly. The blower motor resistor contains different current paths that allow changing voltage levels to the blower motor. A low voltage will cause a low blower speed. Correspondingly higher voltages are supplied to the blower motor to make medium speeds possible. High speed is normally obtained by supplying full battery voltage to the blower motor through use of a blower relay. The blower motor relay is activated by the blower switch. When the blower switch is placed in the high position, a voltage signal is sent to the relay causing the contacts in the relay to close, sending full voltage to the blower motor.

(Lance owned his own auto repair shop for 30 years before retiring in 2006.)

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3 Comments on "Heater Blower Motor"

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In most cases only three or four drops of oil will need to be put
inside the air connector to keep all internal components of the air compressor tools well lubricated.
Making certain the spring rests against the brush,
replace the spring as delicately as you moved it aside.
The smallest air compressors produced by Campbell Hausfeld are pancake style machines whose air tanks
are wide, flattened disc shapes.

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1 year 5 months ago

How can I maintain the blower motor system? Thank you!

2 months 11 days ago

My 05 Pilot makes a squeaking noise when the ac is all the way on low. Sounds like it coming from under the dash. What part do I need to replace?