Stock Temp gauge not working??

[98gstaherns]

Ok it is my 98 gst justa 14b and some bolt ons.. Heres the deal when i got of work today I started my car and drove it for a bit and my temp gauge never went up.. But the heat was fine. It seemed that if i rev the car it would move a lil for some reason but noe it nots moving at all.. Even after the car has been running for about a hour. Everything else is working fine..