EGT Gauge Problem

My Isspro EGT guage is acting goofy. It is getting power and ground becuase the guage will move to about 50 degrees when you turn the power on. But that is it. When you hit the gas, it does not move.

I have not crawled under it to check the thermocoupler connection but I heatshrunk the connection when I put it in.

Any Ideas?? Bad thermocoupler maybe??? It has been in there since December of 02...probably 100,000 miles.

Thanks in advance for the help.

Jay