My temp gauge rises up to the H when i turn my key to on, ive checked the green plug on the back of the housing and changed the sensor and the ground on top. Ive also changed the thermostat. but is some sort of wiring problem.

 

It could be a wire between the cluster and the temp sensor. If you find out which pin it is off the cluster then you run an overlay wire from the cluster to the sensor and see if that fixes it.

If you have super stiff motor mounts it could have rattled some solder joints loose in the circuit board in your cluster as well. Its not common on fc's (that i am aware of) but you could try a different cluster if you happen to have access to one from a friend or spare in the garage or whatever

 

yea after testing all that crap without takin out dash it's just bad temp gauge. put one of those laser themometers on the waterpump and its readin 160* so im just gonna buy one of those jdm temp gauges from the part store.

mad tight jdm

 

look by the oil pressure sender(looks like a bell) on the drivers side of the engine,by the oil filter,
that is where the coolant sender is.
it sounds like the wire fell off.