On arrival I was early of the scheduled time for homeowner to meet me. After she got here I found no signal to orange wire. System running in heat while in cool mode. I tried switching wires but still nothing. There was not enough wires at stat to switch colors I thought a new wire needed to be ran but when jumpered wires at stat the system cooled. The stat needs replaced. Homeowner is going to purchase new Nest stat to be installed. I connected orange wires to yellow to put in cool mode.