Blower motor for heater only works on high....what do you think I need to change. Relay or Resistor.

If the motor blows on med-high but not high or low, it's the resistor.

You probably need a blower motor resistor , it work's through a relay for high speed an resistors lower the speed for low , medium etc... Videos on youtube on how to test ! How to Install Replace Heater AC Fan Speed Resistor 99 07 Ford F250 F350...

should be just above the blower motor. You will need to remove the glove box door to gain access.

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

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.

You replaced the resistor and WHAT relay? The blower motor circuit on a 2007 Dodge Nitro does not use a relay.

The blower resistor gets it's power from the A/C - heater control unit.

If you check for voltage at the blower motor resistor connector (Key on, relay disconnected), the DARK BLUE/GREY wire should be hot when the control switch is on HIGH. The DARK BLUE/VIOLET wire should be hot with the switch in the MEDIUM 2 position.The DARK BLUE/ORANGE wire should be hot with the switch in the MEDIUM 1 position. The DARK BLUE/BROWN wire should be hot with the switch on LOW.

If any of these are not as stated above, then you either have a bad A/C - heater control unit, or faulty wiring between the control unit and the resistor.

CHECK SEE IF HEATER BLOWER MOTOR WORKING, REMOVE HEATER BLOWER MOTOR HOT WIRE HEATER BLOWER MOTOR SEE IF BLOWER MOTOR WORKING BLOWER MOTOR FAULTY OR YOU HAVE FAULTY WIRING AT BLOWER MOTOR AND RESISTOR.

You are probably going to need a blower resistor,High blower runs a seperate relay and the other speeds run through a resistor.Ussually located on the heater box under the dash.

Well you need to change the blower motor relay,if it works for awhile and then goes to only on high again change the relay and the blower motor.The relay is usually cheaper than the blower motor and thats why you should change that first.

Sounds like a bad blower motor resistor. That part is what changes the speed of the blower, and your original blower motor may not be bad if it was running on high only. It may have been the resistor.

sounds like relay to me but what blew it, most likely dry bearings on blower motor causing your noise clean oil fan motor install relay