GRT Oil Temp Probe Wiring

[rph142]

I replaced my Dynon oil temp sensor with the 2 wire GRT FT-LC-01 sensor. It has a gray and a black wire. Does anyone know which wire goes to ground? Maybe it doesn’t matter?

 

[abuura]

I replaced my Dynon oil temp sensor with the 2 wire GRT FT-LC-01 sensor. It has a gray and a black wire. Does anyone know which wire goes to ground? Maybe it doesn’t matter?

I wired the black wire to ground. Works as required.

 

[David Lewis]

I just replaced my original OT probe with the same GRT two-wire probe. I expected the black wire to be ground, but that was wrong. I got wildly incorrect temp readings on the EMS. Once I reversed the wires everything was right again. So in my implementation Gray goes to ground and Black connects to the EMS. Not sure why others have had a different experience. It would perhaps be a good idea to do a test lash up before committing to any wire runs or cutting conductors.

 

[Tankerpilot75]

The GRT EIS setup manual shows a gray wire going to pin 22 for the OAT temp probe.

 

[jclark]

Pin 15, White, for OIL Temperature.

I think the reference was for "OT", not "OAT".

 

[rph142]

Thanks for the replies. I’m going to test wire it first to be sure. Installing the probe was tricky with the wires exiting the back. I had to notch a socket to allow the wires to exit.

 

[David Lewis]

I’m going to test wire it first to be sure. Installing the probe was tricky with the wires exiting the back. I had to notch a socket to allow the wires to exit.

I just used a box wrench because the probe is installed with a crush washer, finger tight plus 135 degrees, then safety wired. No leaks after three engine runs. I hope you’ll post what your test lash up reveals.

 

[rph142]

I installed and tested the probe this morning. Black to ground worked for me and the noise is completely gone.

 

[David Lewis]

Thanks for following up with your result. I wish I knew why my black to ground failed, but the switch to grey is working perfectly. Perhaps polarity doesn’t matter and I had a separate continuity issue that was fixed with the reversal. My readings from the probe are solid as well.