Okay. Let me know how the coolant level and thermostat are. The heater only working on high is a symptom of a faulty blower motor resistor pack. For precautionary measures check your blower relay first. The resistor has 4 settings and settings 1 - 3 have variable resistances for each wire of that setting, setting 4 has NO resistance therefore even when the resistor pack fails the HIGH setting will still work but the other settings will not.
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Friday, March 20th, 2009 AT 10:25 PM