Today I arrived on site to verify the Trane AHU in the attic. Nest tstat is missing power. Nest Thermostat Issue:Identified the Nest thermostat was not functioning correctly. Determined the thermostat lacked a (C) wire connection. Resolution:Recommended a 5-strand cable installation to resolve the (C) wire issue. System Details:This Nest thermostat controls the entire house AC system. The AC system utilizes a Trane condenser. Upon arriving at the property, the client explained to me that the Nest tstat is presenting an alert that the tstat needs charging. I proceeded to verify the nest tstat. I found that the tstats does not have the (C) wire connected. I explained to the customer that he should consider running a new cable from the AHU to the nest tstats to reinstall the tstat and connect the (C) wire to the base of the tstat. The client said he would like to know an estimate to coordinate the installation of a new cable for the Nest tstat. Note: The existing cable only has 3 w