The typical Autometer style EGT gauge uses a type K thermocouple. There are many other types, but K is most commonly used.
A thermocouple is really nothing more than a joint between two dissimilar metals. A small electric charge is created where they meet, and one property of this charge is that it changes with temperature.
The voltage the sensor provides to the gauge is very small, measured in millivolts. That signal is amplified in the little black brainbox (Autometer uses an external amp) and used to drive the needle of the gauge.
To test the sensor, just hook an ohmmeter to see if it is still electrically connected to both ends and not broken somewhere.
If the sensor is OK and the gauge is still stone-dead, then most likely something in the amplifier box is fried. Depending on how the gauge is setup, if there is a 0-5v or 0-10v output from the amplifier to the gauge, you could try hooking up a power supply to the gauge with a couple of volts to see if it still functions and eliminate it as a problem. Make sure you know how the circuit works before doing this.
You can contact the manufacturer to see what they charge to look at it, or maybe get an electronically-inclined friend to test the circuits, they're usually just a simple amplifier with a cold-junction compensation circuit. If the amplifier is external like the Autometer system, you might be able to replace just that component. If it's built into the gauge, you might be able to trade in on a refurbished unit.
Good luck.
A thermocouple is really nothing more than a joint between two dissimilar metals. A small electric charge is created where they meet, and one property of this charge is that it changes with temperature.
The voltage the sensor provides to the gauge is very small, measured in millivolts. That signal is amplified in the little black brainbox (Autometer uses an external amp) and used to drive the needle of the gauge.
To test the sensor, just hook an ohmmeter to see if it is still electrically connected to both ends and not broken somewhere.
If the sensor is OK and the gauge is still stone-dead, then most likely something in the amplifier box is fried. Depending on how the gauge is setup, if there is a 0-5v or 0-10v output from the amplifier to the gauge, you could try hooking up a power supply to the gauge with a couple of volts to see if it still functions and eliminate it as a problem. Make sure you know how the circuit works before doing this.
You can contact the manufacturer to see what they charge to look at it, or maybe get an electronically-inclined friend to test the circuits, they're usually just a simple amplifier with a cold-junction compensation circuit. If the amplifier is external like the Autometer system, you might be able to replace just that component. If it's built into the gauge, you might be able to trade in on a refurbished unit.
Good luck.
