Coolant Temp Gauge not working

[catbobjr89]

My coolant temp gauge in my dash is always below cool. Sensor is plugged in, could it be wirirng, if so, where at?

[navysnail]

does it move at all?

[vancouverbc]

The sensor for the instrument panel temperature gauge has black connector and is right next to red connector. it only has one wire.

it is ground so i assume the quality of the ground changes as temp changes resistance of thermistor. you might try measuring continuity from sensor to engine ground . resistance shoud vary with temp.

Modified by vancouverbc at 3:49 AM 7/7/2006
Modified by vancouverbc at 10:39 PM 7/7/2006

[vancouverbc]

if you connect wire from instrument panel directly to ground you might be simulating high temp and gauge should show high temp. might blow gauge. you could use a resistor to test.

[vancouverbc]

I was right. I tested my instrument cluster temp sensor today and measured 4.5 ohms when engine was cold and 320 ohms when engine was right in the middle of gauge. I also hooked sensor directly to ground and needle went very high( off the scale). the sensor is just a thermistor. increase temp reduces resistence of thermistor and vice versa.

[catbobjr89]

How do i know which wire to test?

[vancouverbc]

there is only one wire. unplug connector at sensor. stick small screw drive in plastic connector where the sensor terminal normally sticks in. connect from screw driver metal to engine ground. your temp gauge should go to high. if not, the wiring or instrument cluster is the problem. to test sensor, just put one probe of ohm meter on sensor terminal and one probe on engine ground. you should get reading close to mine. if not, the sensor is the problem. you have a 300z ? your ohm readings may be different but same principal. resistance should go up when temp goes down and vice versa.

it is the plug closest to red plug( to the right).(1991 240sx pic)

Modified by vancouverbc at 1:41 PM 7/10/2005

Modified by vancouverbc at 1:46 PM 7/10/2005
Modified by vancouverbc at 6:08 PM 7/10/2005

[XoticImports]

Jermey, i have a ohm meter and would like to also help you with this, and by the way, the above picture is a ka24de = not your moter and i want to help you figure out your intake too. (check your other posts)