ok so I replaced my intake gasket and I found that I broke the temp sending unit in the left head so I replaced that now my temp gauge still reads way past hot almost pointing at the bottom of the scale. anyone know what voltage should be going to that its a two wire sending unit im guessing that it reads resistance how do I check the wire going to it

 

Here is a ohm's chart, think ref v is 5. Not sure but it sounds like a short to ground.
testing gm coolant temperature sensors

 

thanks I got it I just disconnected bat for about 10 min reconnected and it now works

 

Hey man, that works too, the good old unplug and plug. Great!