Nest Learning Thermostat Fan Not Working

[Danimal11]

We just installed our Nest Learning Thermostat a few weeks ago. When we did the install and the test, everything worked great. The fan kicked on immediately, cooled and heated without a problem.

We tried to turn on our A/C yesterday, attempted to drop the temperature about 6 degrees. The thermostat said we'd get to temp in about an hour. The outside air handler kicked on and the inside fan blew for about 5 minutes, then stopped. The outside air handler continued to run, while the inside fan never came back on.

So we know the fan works, and the thermostat controlled everything well in the test, but when running a cooling cycle the inside fan only works for the first 5 minutes...

[CoolingWizard]

@Danimal11 ,

You will need to get a Volt Ohm multimeter.  You will go to your air handler and locate the part of the cabinet the thermostat wire enters.  That will be the cover you will need to remove.  Once it is off, you need to check the AC Voltage arriving on the G wire. If there is a circuit board look for the G terminal. Set you meter to AC Power.  Put one lead on the Common, the other lead on the G.  Have someone turn the cooling on and verify that the 24VAC +/- 5VAC is present and when the fan stops, does the 24VAC go away or does the voltage remain.  

AC Cooling Wizard

[Danimal11]

Thanks @CoolingWizard for the response. I will get that Volt Ohm multimeter and see what it comes back with.

We were mapping/labeling our electrical box (very old and half were not labeled) last night and shut down the outdoor condenser unit and the indoor air handler in the process. After the restart the A/C worked for us, and the fan performed well so for the time being it seems to be working ok,  but we will still test it out.