Coolant Temp Sensor issue

[1Bad86]

Recently installed TPIS Big Mouth Intake manifold base plate. I replaced all the sensors with new ones. To make a long story short, now my coolant temp gauge always reads "Lo". I have checked everything else and system is working great. I also installed a 170 degree thermostat and 190 degree fan switch and these seem to be operating correctly. I tried putting the old coolant temp. sensor back in cause I knew it worked but still the same result. I get no SES codes or anything. Any ideas or am I just missing something obvious?:confused

 

[geekinavette]

Disconnect the wire from the sensor and put an ohm-meter between the sensor terminal and ground, and see if the resistance changes (goes down) as the engine heats up. If it does then you've likely got a broken connection between the sensor and the gauge.

Bill

 

[scorp508]

Here is where things get interesting.

Forgive me because I can't remember 100%, but if your 86 is just like my 87 then there are two coolant sensors on your car. One between cylinders 6 & 8 and one on the front of your intake manifold.

The one between 6/8 is for the display on your digidash. The one on the front of the manifold is for the ECM. I know it sounds wierd, but it provides a backup system.

I can never remember if 86 is the same. The iron/aluminum head change gets the best of me.

 

[1Bad86]

Mine is exactly opposite. I know because the fan switch went between 6 & 8 and goes only to fan relay. I think it has to be a poor connection between the sensor and the Istnt. cluster. At least that is what I have been told. No luck yet though. Thanks to all who are helping me out here.