Temp gauge not working

[joecassie]

I have a 1986 325E, and I have two temp gauge sensors what can I do so I can only use one.

[Thrizzle]

Well what motor do you have?

There is usually two sensors, one for the ecu, one for the gauge on the cluster.

[dashboardmonkey]

you have to switch the sensor towards the rear to the stock e30 sensor

[frankie591]

The blue top sensor runs the e36 ecu. Keep that one as is. The black top sensor runs the e36 gauges. Change that sensor to the brown top single pin e30 sensor. That will ensure that your gauge works properly.

[joecassie]

I have a s50 and I'm not sure what sensor it is. Is it the top one or the bottom one because I'm using the top one with the small connectors and it is getting power but it is not working.

[Thrizzle]

There's two coolant sensors, one towards the front of the head, and one right behind it, nothing is on top or bottom.

Front sensor should be blue top, don't touch that. Rear one should be brown top 1 pin from an e30. If it's not, switch it out or your cluster temp gauge won't be able to read it.