EGT probe failing?

[shackwrrr]

Installed the egt gauge the other day and it worked fine. Now it stays below 0 and only sometimes comes up to around 1100. If it give it throttle it drops back to 0. I tried re doing the ground and using different power sources but it still does it. Probe bad? It was installed in the Mani for a long time with no gauge hooked up.

Its an auto meter ultralite.

[wallace]

You should be able to check the probe with a good meter. You can find the range for your type of thermocouple on the internet. Is it an open element or is it encased?

[acannell]

Measuring a thermocouple directly with a multimeter requires some consideration.

For a type K, the voltage you measure will be approximately 40uV (0.00004V) per degree C _difference_ between the probe type and the location you make the measurement at. So if your engine is idling and your thermocouple tip is at around 900F, and you are making the measurement by holding a multimeter on the thermocouple wire ends (or connector) inside the cab at room temperature, thats about 450C difference, which equates to about 18mV measured. If you use a crappy multimeter don't trust the results. This is a sensitive measurement and should be done with a Fluke or similar meter in good condition.

If you measure a thermocouple sitting on a table next to you at room temperature, you will get around 0V because the temperature difference is around 0.