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: ----
http://repairhelpcenter.blogspot.in/2012/02/blower-motor-replacing-for-all-vehicles.html
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These will help.
Thanks.
FAN NOT WORKING
It can be issue with faulty motor or its faulty fan control relay.
Both are to be inspected.
Test volt at fan relay and fan motor.
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For more help, I suggest you to go through the troubleshooting link mentioned below:-----
Click the link below: ------
Engine Cooling Fan not Working http://technoanswers.blogspot.com/2012/11/overheating-radiator-fan-not-working.html---------These will help.Thanks.
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