Question about 1998 GMC Sierra

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1996 s-10 p/u non-working heater blower

I tested the motor,it's fine. when I unplug from the motor speed resistor,The fan will work on high speed only.If I plug back in ,nothing......probably the resistor? thanks

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  • jjhorst Nov 29, 2008

    The heater core would be a seperate issue in that it"s part of the cooling system,whereas, this appears to be an electrical problem! Thanks for your input,though! I'm trying to find out if there is a relay,and i'm thinkin so at this point.

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No more than likely a heater core issue take it down to a local garge and have them do a test on the heater core

Posted on Nov 29, 2008

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2 Answers

How do you know if your blower resistor is bad?


Unlikely a blower motor resistor problem. If the resistor is faulty. the fan speeds will not work/fail on the lower speeds. High speed will normally always work. If the fan is non operational suspect a fan motor issue.Bad fan motor/switch/wiring to it

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98 buick heater stop working


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

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1 Answer

My heater blowers dnt work and i need to knw where i can locate the resister blocks for my heater blowers so i can ghange them


Its located under dash,or near glove box.

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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: ----

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

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1 Answer

Heater is not working


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.

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Nov 28, 2012 | 1988 Honda Accord 4 Door

2 Answers

Location of the resister for the heater fan 350 ford 2006


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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: ----

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

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These will help.

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Heater / air conditioner fan control doesn't engage fan. Previously, it only worked in high speed.


I would replace the blower motor resistor first then see if that corrects this. The resistor is located next to the blower motor under the dash.

Jul 16, 2012 | Cars & Trucks

1 Answer

I would like to know how I can fix the heater in a 89 gmc k1500 with a 350 engine and no air. I tried a new heater motor and still not working. The Fuse is also good.


This is a blower motor not working tip I posted a little while back.

Blower motor problems are a pretty common topic. This is a basic guide on how to diagnose the problem and will work for most vehicles.

The diagram is generic and loosely based on GM's setup and more specifically a Silverado. Most manufacturers have a similar setup and the only major differences would be a ground side control (instead of the switch supplying power to the resistor it would be grounding the power from the resistor if this is the case you test light would need to be connected to power to test the switch) and late model Chrysler minivans (they use a module that looks for a difference in a/c voltage from the switch)

If the blower works on high only than likely the resistor assembly is the culprit since power to the blower essentially bypasses all of the resistors and/or the resistor assembly entirely. The reason why none off the other speeds will work is that the resistor or the circuit for the speed four setting has burned out. The lower the setting the more resistance you need to drop the voltage to the blower. The first speed setting requires all four resistors to drop the voltage enough to turn the blower at its slowest speed. Speed 2 needs to turn the blower a little faster so it uses three resistors. Speed 3 uses two resistors and speed 4 uses one.

In some cases the fan will work on high and speed setting 4. The likely cause for this is the speed 3 resistor or circuit has burned out. Speed 4 still works because it doesn't use the lower speeds resistors to control the speed of the blower. If the speed 2 resistor burns out than speed 1 and 2 will not work but 3, 4 and high will continue to work. If the speed 1 resistor burns out than speeds 2, 3, 4, and high will continue to work.

This leads us to how do we know if its the resistor or the switch or the blower. If the blower works on high than we know the blower works. That leaves us with either the switch or the resistor assembly (there are many other possibilities) which can be easily tested with a test light (or a voltmeter if you choose) The first thing to do is locate the resistor assemble. They can be behind the glove box, under the dash close to the blower motor or under the hood, again usually close to the blower motor. It will typically have 5 to six wires going to it. We'll start by unplugging the connector, turning the key on and connecting your test light to ground.

1.Turn the switch to high and backprobe all the wires. Two of them should illuminate the test light. In the diagram below this would be wire E & F. If you don't have a diagram then hold the test light on one of the two wires and move the switch to another speed setting. the wire that continuously illuminates the test light regardless of the switch position will be the constant power for high blower speed and will not need to be rechecked in the following steps.

2. Turn the switch to the next lowest setting. Backprobe the remaining wires to see if one of them illuminates the test light. Repeat until you have checked all of the speed settings.

3. If the test light has illuminated a different wire for each setting then we can reasonably assume that the switch is functioning as intended and the source of the problem is the blower resistor.

If you find one or more settings (but not all the settings) on the switch that does not illuminate the test light on any wire than we can reasonably assume that the switch has failed.

There are a few other things that can cause blower motors not to work as intended. The switch or the resistor assembly are the two most common problems.

342697e.jpg

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3 Answers

I only get the fan to work on high speed, the lower speeds do not work


Hi!!
The Blower Motor Resistor also called Manual Temp. Control resistor), is fried, replace. The price with floor console $25 and without floor console $65. here is a pic.
87b9810.jpg

the resistor is located on the blower motor housing, fastened by two screws. It is the part where the electrical plug connects, the plug on the pic. goes to the blower motor.
A HELPFUL - 4 THUMBS rating for this solution would be greatly appreciated. Thank you for using FixYa.

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3 Answers

Blower Motor quit. I checked fuses, they're good.


Run a jumper to the motor directly from the battery, if it works you have wiring problem, if not replace the blower.

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most likely ur multi-switch[fan selector switch] test out put for the other speeds if no output replace switch if good test motor

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