Tempe gauge pegs when connected directly to a ground using the green wire I've rung the wires and this black wire in the picture also goes to the back of the gauge so I assume it's a ground not sure if this wire also has to be hooked up the car calls for a one wire sender 1984 Camaro 305

 

What is connected to the Temp sending unit right now? The wire for that is supposed to be dark green...

 

Nothing I bought the car no engine installed a 95 350 tbi converted to carburetor

 

I've tried 2 new senders like I said the only way the gauge will do anything is if you hook it to ground

 

Since your saying that sender is a " 1 wire". It would work by a ground connected to engine block. The return wire from the sensor would go to the guage. The resistance would change depending on Temp *F. Thats why the guage pegs out when you put a straight ground to it.

 

So is the question about the green wire of the black wire?
Do you have continuity to ground on the black wire? If so it should be landed to a ground, As you may know funny things happen when grounds aren't present.
That green wire would also branch off and go to the ignition switch, could check continuity to the ignition switch to verify this is the correct green wire to the temp sender for the gauge

 

Ahh look at that drawing i bet i know what you got going on there! The right diagram incorrecly labels a switch a sensor or sender. This is really a switch that turns on at lets say 210F or high temp then passes a ground to light up the lamp on dash.
The diagram on the left shows a model that had guages and would use a different sender.

that being said, Your most likely buying a switch and not a sender. The wire to the ignition switch is optional. This would apply a ground to lamp test and sweep the guage.

you can verify this buy the symbols on the diagram for the senders.

 

Haven't had a chance to get back to the Camaro for a few weeks
1. I checked to make sure the engine is properly grounded and I have 12 volts when I go from positive terminal to engine block
2. Verified at start temp gauge pins
3. Verified temp gauge pins when connected straight to ground
4. After verifying let engine run for approximately 30 minutes and gauge does nothing car is up to operating temperature
5. Bought a 3rd sender unit and tried that using Teflon tape on 1/3 Rd of the threads to be sure I'm grounded and still does not work

AT THIS POINT IM GOING TO BUY AN AFTERMARKET GAUGE FOR THE TIME BEING AS I HAVE NO IDEA WHERE TO GO FROM HERE.....
I've checked everything that has been mentioned and I can't figure it out💩💩💩

 

I don't use Teflon tape for that...

 

I can try removing the Teflon tape but there plenty of metal contacting the block so I'm not optimistic that's what it is

 

Removed Teflon tape and applied thread sealant still does not work!