Google Nest E74 Code Power Wire

[Tphan85]

Getting an E74 wiring issue power wire. Reset the AC fuse box a few times and still not working. Below is the old wire and plugged the red wire to RH to the nest. 

 

[Tphan85]

 

Here is a pic of the wires I connected everything to. If any recommendations on how to fix this, let me know. 

[CoolingWizard]

Did you make sure to turn the power off to the HVAC air handler before you started moving wires around?  If you shorted a wire accidentally, you might have blown the 3amp control board fuse.  

The AC Cooling Wizard 

[Jenelyn_O]

Hi there,
 

Thanks for reaching out. I'm sorry for the delay. How's your Nest Learning Thermostat? Is it still showing E74? You can visit this support article to know more about it.
 

I appreciate your help, @CoolingWizard.
 

Best,

Jenelyn

[Markjosephp]

Hey there,

I wanted to stop by and see how I could help.

Thanks for assisting here, Jenelyn.

@Tphan85, the common wire may not be properly grounded, so the system uses power sharing but doesn’t get enough energy. Try removing the C wire and leaving it disconnected to see if the wiring report disappears. If so, you don't need to connect it, as the Nest Learning Thermostat can charge its built-in battery using your heating and cooling wires, but there are still situations where you may need to reconnect it.

Please let us know how it goes.

Regards,
Mark

[Dan_A]

Hi folks,

We haven't heard from you in a while so we'll be locking this thread if there is no update within 24 hours. If you need assistance or want to discuss topics, feel free to start a new thread.
 

Cheers,

Dan