I am hoping to be able to upgrade to a smart thermostat but unfortunately my furnace doesn't have the "easy" option with an obvious C terminal.
My furnace is OLD but it actually has the full 5 wires pulled to it although only 4 of them are in use/connected. All 4 are attached to the appropriately marked terminal at the Thermostat (see picture) but then it's a bit of a rats nest at the furnace so I am trying to figure out where the C wire would go to make the smart thermostat work.
Is there another wire I can piggy back off of at the furnace to bring the necessary power to the smart thermostat? Does anything in these pictures give you any idea where to attach the blue/C wire at the furnace? Any help you can offer would be much appreciated.
Thanks in advance and feel free to respond if you need a better look at anything from these pictures.