My CB1200 exhaust fan quit shutting off after the 10-20 minutes when I would plug it in (it would also spontaneously turn on randomly before it failed entirely). After doing some troubleshooting, I decided the control box had gone bad so I replaced it. The old one was a clear box (it's from 2019 so not old) and the new one is a clear box (set to #1) so I just swapped them out and ignored the green grounding wire. The exhaust fan shuts off after 10-20 mins now when plugged in with the new control box. The weird thing is the red call light below fan lo/hi switch comes on when plugged in too and that stays on. I put the old control box back in and the red call light is on continuously (of course the exhaust fan also never shuts off) so I don't know if this is normal or if I still have a problem. I thought it should only turn on when I turn the thermostat on. I'm afraid to turn the thermostat on and try it until I know for sure. I did add the green grounding wire (which wasn't there with the old clear control box), and the exhaust fan still turns off properly but the red call light stays on.