This is my furnace board. I don't see anything with a C terminal. Are there any connections on this board that I can use as a "C" terminal?
Below is the thermostat I'm trying to hook up. This is how it was wired at my old house.
Is this wiring correct?
See the white wire coming from the cable to the A/C compressor? Since the red wire in that cable goes to the Y terminal, the white wire in that cable has only one place it can go for the A/C to work, and that is the C terminal on the control board or its equivalent transformer terminal.
P.S. as to how you have the thermostat hooked up? It's spot on.
The documentation for that control board can be found here
ST9160A-C Electronic Fan Timers - Honeywell https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-1057.pdf
As @ratchet freak mentioned, the wiring needs to be redone. The inside of a furnace is noisy, dusty and subject to vibration and temperature variations. Loose connections create problems that are difficult to diagnose.
The end of the wires should be fashioned into a reversed question mark so they hook properly to the screw terminals.
https://www.hunker.com/13414272/proper-technique-to-wrap-an-electrical-wire-around-a-screw-terminal
