Auto body repair & detailing: Temperature Gauge on Toyota Tacoma, toyota tacoma 4x4, temperature gauge

Question
The temperature gauge on my 2000 Toyota Tacoma 4x4 indicates that my engine is warm even when the engine is cold. After the truck has warmed up then the temperature gauge falls all the way to cold and then the temperature gauge starts to go back up to where it should be. Also, when I turn the engine off the needle falls back to cold, that is why I know the needle isnt working correctly and it isn't a problem with my engine. Why is this happening, or what could it be?

Answer
RALPH....NOT A MECHANIC BUT I'LL BE HAPPY TO GIVE IT A SHOT.
IT COULD BE THAT THE GAUGE IS CONTROLLED BY A TEMPERATURE SENSOR WHICH IS GOOFY OR
IT MAY BE A BAD GROUND CONNECTED TO THE SENSOR/TRUCK. I DON'T KNOW WHERE THE ENGINE TEMPERATURE SENDING SENSOR IS LOCATED.

GOOD LUCK