This is not an overheating issue since it's not even running yet. While messing with the distributor on my 99 blazer I forgot to put back the 3 driver side spark plug wires. when I turned over the engine the temperature gauge went all the way to the 5 o'clock position and stayed there. I tried disconnecting the battery but that didn't fix it. Any ideas?

 

you sure you didnt accidently forget to hook up a temp sensor? thats what it sounds like to me

 

Nope...everything was hooked up. I'm not sure what I did but after getting the car started a couple of hours later it went back to normal. Previously I disconnected the negative battery terminal. Perhaps disconnecting the positive fixed it...I don't know. Maybe it's one of GM's weird ways of telling you somethings wrong.