91 civic temp gauge reads cold ( actually doesn't move ) I have replaced the sending unit and the temp gauge. The engine does warm up normally and the cooling fan comes on when it should. I have found no breaks in the wiring that is under the hood (checked with ohm meter) I don't know about under the dash. All connections at the back of the cluster look good.

 

hmm maybe bad sending unit, or guage... i'm a mechanic, and i get bad parts from the parts stores all the time...

 

I've grounded the wires going to the gauge at the sending unit. Still no movement from the gauge. I assume there is no fuse in the circuit? I can't find one in the fuse box.

 

Look up the temperature sensor pin in the gauge cluster connection.
Disconnect the connection to the cluster.
Disconnect the lead from the temperature sensor.
Attach an alligator clip probe to lead from the temperature sensor.
Set your mulitimeter to continuity check.
With the other probe, touch the temperature sensor pin in the gauge cluster connection. (Is there continuity from the temp sensor to the gauge cluster?)

Also, check the ground to the gauge cluster. (I had a few wierd readings: temp gauge spiking, speed sensor error code, and turn signal lights flashing strangely. Due to a bad ground at the gauge cluster.)