# 3 coolant temp sensors?



## anthonyleehamilton (Sep 2, 2012)

i have a white 1990 jetta gl running digifant I. 
Connected to the front of the head is a housing containing a black temp sensor and a blue one. then on the right side of the head there is a housing containing a tan temp sensor (could have been white at one point, idk)
i know the black temp sensor sends info to the cluster.. and the blue one sends info to the computer.. so what does the tan/white one do? 

Here's a couple photos showing the location of the mystery sensor


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## ps2375 (Aug 13, 2003)

One of those is an AC cutoff, black or blue, I bet the blue is for the dash and the white one goes to the ECU. Pull the connector off of the black and blue ones and see is the dash works and if the AC works. One at a time of course.


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## WaterWheels (Aug 14, 2005)

Blue one is for the Digifant computer, black one is for the temperature gauge in the dash and the circled one is listed as a "temperature switch". I would guess as was stated it is for the A/C cut-off but only the diesel models say that is what it is for. Color listed is graywhite and not tan, are you sure about the color?


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## ps2375 (Aug 13, 2003)

If you look in the Bently Manual, the color code on the wires will tell you what they are for.


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## JettaKid90 (Jun 19, 2009)

http://www.autohausaz.com/search/pr...ir System&[email protected] Temperature Sensor 

Hope this helps.


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## ziddey (Apr 16, 2006)

check that ground


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## starksan (Mar 30, 2013)

There's also the CTS attached to the lower driver side of the radiator.


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## Glegor (Mar 31, 2008)

starksan said:


> There's also the CTS attached to the lower driver side of the radiator.


 thats only for the rad fans tho..


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## vswager (Dec 15, 2012)

ziddey said:


> check that ground


:laugh:


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