I just installed a Glow Shift EGT Gauge and sensor. Before the ignition is even turned on, it reads at maximum. When I start the motor, it goes down to about 1600 for an instant and then pegs again at maximum. I checked the wiring and all seems in order. Any thoughts on what I can do to trouble shoot?

1998 12 Valve Automatic.

 

check connections again it should read zero, then when switched on it will move full sweep and come back to rest at temp. if the wiring is not the issue sounds like you got a warranty issue.

 

Make sure you are tapped into the right 12v key on source and grounded good.