My 83 T/A's temp gauge isnt working. Its a H code with a nonCCC quadrajet. I found the Dark Green wire broken off, spliced a new wire and flat connector onto it, and plugged it into the existing sensor, no help.
I tried a few other sensors (single wire), also no help. Put a rheostat inline with it to see what the gauge wanted to see.

Straight to ground pegs the gauge as it should.
170 ohms is about at the 158* mark.
93 ohms gives me half scale on the gauge, about 220*
57 ohms is puts it in the red on the scale at 260*

Ive tested a few sensors that Summit, Advance, and Oreillys showed as correct for 1983 Firebird, all different numbers of course. The sensors ive tried so far have matched pretty closely with the GM sensor charts ive found online.
450 ohm is 160* on the chart
145 ohm is 220* on the chart
75 ohms is 260* on the chart and so on...

The gauge needs lower resistance than what these sensors im getting are providing, so the gauge isnt working.
So am i just getting the wrong sensors? Does anyone have the correct sensor number? Or is there a way to calibrate the temp gauge itself to read correctly to match the sensor numbers im getting?
Am I slowly losing my mind?

 

trouble could be in several places including the instrument cluster: over a few decades,bad connection can develop where metal clips that studs on back of gauges plug into connect to the copper traces of the "printed circuit".While the cluster is out,ohm the circuit from the sender plug to the gauge connection.Gauge itself is rarely bad.I think GM used same sender from ~mid-1950s to '95 at least.

 

No doubt. I'll double check my splice and pull the cluster out and see what I can see back there. Maybe there is something upping the resistance to the gauge.