Heater/ a/c blower motor only works on low speed no matter what speed its set at

The blower motor relay is energized when the Blower Motor Control is set to the High position. This removes the blower motor resistors from the circuit and battery voltage is then applied directly from the HVAC BLO fuse (RH IP Accessory Wiring Junction Block) to the blower motor though the relay switch contacts. The blower motor then runs at high speed.

HVAC Blower Controls Circuit Description
The blower motor is a variable speed motor. The motor operates at a higher rate when voltage is increased to the maximum level.
The blower motor resistors reduce the voltage supplied from the A/C FAN fuse (LH IP Accessory Wiring Junction Block) when the blower control is set at low and medium speeds (speeds 1-4). The blower motor relay is energized when the Blower Motor Control is set to the High position. This removes the blower motor resistors from the circuit and battery voltage is then applied directly from the HVAC BLO fuse (RH IP Accessory Wiring Junction Block) to the blower motor though the relay switch contacts. The blower motor then runs at high speed.

blower is not running full speed? on high?
the blower has this resistor block on many cars,
that fail, easy. (burn up) but not ever on high. (bypassed then)
a big clue that. no?
is the blower slow or just dampers closed and cant feel it.
surly you know the sound of your blower on high, sound !
air flow is a whole other more complex matter.
also is battery rested voltage at 12.6v? if not you have discharged battery making fan weak ( power = volts times current. so....)

Most likely the blower motor resistor or the fise for the low speeds. The high setting for the blower motor is on a separate circuit than the other lower settings.

Its located under dash,or near glove box.

The dash panel lower side has to be out.

HEATER BLOWER MOTOR

Its faulty blower motor resistor. The low and medium speed on blower motor is controlled by resistor and its actual speed is high. So because resistor is not working, blower motors actual speed which is high is working.

It can be faulty blower motor or faulty blower motor resistor. Get the blower motor inspected. If it's faulty it has to be replaced.

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For blower motor testing and replacing, check the link below: ----

Blower motor Testing/replacing for all vehicles?

http://repairhelpcenter.blogspot.in/2012/02/blower-motor-replacing-for-all-vehicles.html

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These will help.

Thanks.

HEATER BLOWER MOTOR

Its faulty blower motor resistor. The low and medium speed on blower motor is controlled by resistor and its actual speed is high. So because resistor is not working, blower motors actual speed which is high is working.

It can be faulty blower motor or faulty blower motor resistor. Get the blower motor inspected. If it's faulty it has to be replaced.

=======

For blower motor testing and replacing, check the link below: ----

Blower motor Testing/replacing for all vehicles?

http://repairhelpcenter.blogspot.in/2012/02/blower-motor-replacing-for-all-vehicles.html

------------

These will help.

Thanks.

With the key on and the blower speed set to high tap the blower motor with a rubber mallet. The key word is tap! If the blower starts working it will need to be replaced.

The blower is located under the passenger side of the dash right above where the passengers feet would be. There is usually a plastic cover that needs to be removed to gain access to the blower motor.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Sometimes the electrical connecter burns on the back side of your switch. You can get just the switch and replace it and repair the connecter when possible.

This could be a few different things:

1.Check the power and ground connections on your blower motor, corrosion can cause high resistance and a slow blower speed.

2. Check your available voltage at the blower motor on the different settings. it should vary with high supplying 12volts, make sure to do this check with the blower motor still plugged in.

3. Connect the blower to a 12v power source and see if it runs at high speed.

If all else fails i would check your resistor pack, i would not suspect this because when it fails you usually just loose all speeds except for high, but it could happen.

The problem is the blower motor speed control resistor, it is located near the blower motor in the housing.