# Temperature sensor on a Blazer

**URL:** <https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, blazer\
**Created:** [September 6, 2009, 2:02am UTC](https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195 "2009-09-06T02:02:30Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![georgegrimes](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@georgegrimes](https://community.cartalk.com/u/georgegrimes)\
**Post date:** [September 6, 2009, 2:02am UTC](https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195/1 "2009-09-06T02:02:30Z")

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After my 2002 Blazer had some front end collision damage repaired, the temperature shown in the rear view mirror display always shows to be too high. Some times it is as much as 15 degrees too high. Where is the sensor located? How can I fix the problem?

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**Author:** ![waterboy](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/waterboy/32/764_2.png) [@waterboy](https://community.cartalk.com/u/waterboy)\
**Post date:** [September 6, 2009, 2:42am UTC](https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195/2 "2009-09-06T02:42:48Z")

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I am not sure where the sensor is located, but I doubt that is the issue. You need to find a reputable mechanic that can diagnose any coolant system issues, be it radiator, pressure, or other problems.

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**Author:** ![Triedaq](https://avatars.discourse-cdn.com/v4/letter/t/65b543/32.png) [@Triedaq](https://community.cartalk.com/u/Triedaq)\
**Post date:** [September 6, 2009, 2:47am UTC](https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195/3 "2009-09-06T02:47:40Z")

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I think that the OP is asking about the sensor that feeds the thermometer on the rear view mirror. I don’t think this has any connection with the cooling system of the engine. I think that this just gives the outside temperature. This is a handy feature for winter driving so that one has an idea about whether or not the roads may freeze over. I have absolutely no idea where this sensor is located.

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**Author:** ![edb1961](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/edb1961/32/122_2.png) [@edb1961](https://community.cartalk.com/u/edb1961)\
**Post date:** [September 6, 2009, 4:54am UTC](https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195/4 "2009-09-06T04:54:06Z")

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This might help.

[http://autorepair.about.com/library/illustrations/bl420a-lib.htm](http://autorepair.about.com/library/illustrations/bl420a-lib.htm)

Ed B.

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**Author:** ![georgegrimes](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@georgegrimes](https://community.cartalk.com/u/georgegrimes)\
**Post date:** [September 7, 2009, 5:13am UTC](https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195/5 "2009-09-07T05:13:27Z")

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My problem has nothing to do with the cooling system (coolant, radiator, pressure, etc.). The temperature that I am talking about is the exterior air temperature and it is displayed in the lower right corner of the rear view mirror along with the compass heading. Since the repair, the temperature reading is always high and higher after the engine warms up. I suspect that something is interfering with the sensor’s access to outside air. I thought that it might be sensing air that had been warmed by the engine instead.

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**Author:** ![georgegrimes](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@georgegrimes](https://community.cartalk.com/u/georgegrimes)\
**Post date:** [September 7, 2009, 5:14am UTC](https://community.cartalk.com/t/temperature-sensor-on-a-blazer/36195/6 "2009-09-07T05:14:35Z")

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Thank you. That was helpful.

George