[jdc0222]

Hello - Hoping for a bit of advice here about an attic fan that stopped working

The attic exhaust fan stopped working last year. The wiring runs from another light bulb in the attic, which works fine. The wires coming off of that light bulb first go through a standard looking light switch (does not control the light, but seems control the power towards the thermostat/fan), then goes through a thermostat switch to control the fan, then to the fan itself.

Can anyone tell me how to figure out if it's the fan, the thermostat switch, or the actual light switch that has the problem?

Thanks,
Jon