Hi , getting close to starting my car after a year and a half restoration and did a test run tonight of the cluster and dash . All seems to be good except the temp gauge went all the way over past 260 and stayed there . The car has a brand new dash and engine harness and new a/c delco gauges. I haven’t checked anything yet as I am a little disappointed . Any ideas enclosed is a picture of the gauge after the key was turned on
Bob

 

Do you have it plugged in backwards?

 

 

yes it is plug only goes on one way but i did some reading on the forum and the ac delco #6402594 replacement gauges came with instruction to not transfer the resistor from old gauge to the new which i believe i did. I don't have much recourse as i bought the gauge from a vendor who buys closeout's and there was no paper work inside ( it has been a very costly lesson as this is not the first item i have issues with. Next question can i remove the gauge without the cluster coming out
thank you for any help
Bob

 

I might have an easy fix for you without taking the gauge out. Try this and post back and I may have a way to quickly and easily move it to the correct part of the gauge.
Quick test, with the key on, if you short the green wire that goes to the sensor on the intake directly to ground, does the needle move clockwise to the left side of the gauge still sort of pointing down? Or does it not move at all?

 

Went all the way to the 5:00 position and stays there
thanks Bob

 

Doesn't move if you remove the green wire at the sensor and then touch to ground and then away from ground? No needle movement with those two actions with key on?
If not, do you have 12v on the pink wire on the gauge? If you do have 12v on the pink, grounding the green wire should make it swing to the other side. If not, either gauge is open, or one of those two wires in not connected. The green passes through the bulkhead connector, the pink comes from the fuse box to operate the fuel gauge, b/u lights, and park brake warning lamp. If those other things work, it's not the fuse or the ignition switch.
All that information is not so much to correct the gauge as determine if the gauge is working at all. I need to know if the needle moves with 12v on one side and momentarily grounding the other side of the gauge. If that happens, we might be able to invert the gauge by VERY momentarily reversing the voltage to the gauge to flip the needle back to the correct side of the balance point.
Still, you could have a bad gauge or bad wiring. If you have access to another gauge, you might try connecting it before you remove the one in your car. The gauge should be reading below 100* on the upper left. Yours appears to be 180 degrees out.