Wire connection from Observer Thermostat (4 wires: DX+, R, C, and DX-) to Nest 3 thermostat

[StanChan]

Please provide inputs for Observer (4 wires; DX+, R, C and D-) to Nest 3 Learning Thermostat. How to wire it up?

Thanks!

[ciprianocoche]

Hi StanChan,
 

Thank you for reaching out to the Google Nest Community team. I understand the inconvenience you're having when trying to find compatible wires with your Nest thermostat. No worries; I will do my best to help you find a solution.

While reviewing the scene, I can see there are some wires. You might check the compatibility using the Compatibility Checker. There, you will make sure the existing wires you have from your HVAC are compatible with the Nest thermostat you want to use. 
Please feel free to let me know once you're done.

Best Regards,
Jonathan