# Will a stuck thermostat turn the check engine light on?



## Booty_Hunter (Jun 10, 2014)

My blower motor has stopped working on all settings. I read that if the resistor is bad it will still work on at least 1 of the settings, mine works on none. I also read if it is not blowing at all it could mean the thermostat is stuck, if its stuck the car wont let the motor turn on. 

*My question is, if the thermostat is stuck, will the check engine light turn on?* There is no check engine light, and the car is not over heating. I have not checked the fuses yet, will do that tomorrow. Anything else to check? 

Thanks in advance.


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## worthirt (May 21, 2013)

along with the fuses, check the blower motor itself. A stuck thermostat may kick the light, but it may not. Usually the thermostat is not a monitored parameter on the ecu, but the other systems are.


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## rogoman (Dec 16, 2004)

Booty_Hunter said:


> My blower motor has stopped working on all settings. I read that if the resistor is bad it will still work on at least 1 of the settings, mine works on none. I also read if it is not blowing at all it could mean the thermostat is stuck, if its stuck the car wont let the motor turn on.
> 
> *My question is, if the thermostat is stuck, will the check engine light turn on?* There is no check engine light, and the car is not over heating. I have not checked the fuses yet, will do that tomorrow. Anything else to check?
> 
> Thanks in advance.


If the blower motor does not work at all on any setting, it's generally due to a bad motor, blown fuse, bad fan resistor or bad harness connection. A bad thermostat has no effect on the blower motor or the 'check engine light'. If the temperature gauge normally sits at the proper position while operating the car, the thermostat is most likely OK; if it was stuck, depending where it's stuck, then the gauge may show below normal or above normal temperatures.


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