I have a aprilaire 400 and am tracking down two spare wires (yeah I know)
JA: I'll do all I can to help. How long have you been dealing with this?
Customer: This has been like this for awhile. Hence my confusion. The yellow wires are hooked to solenoid so thats good. From quick search I am believing these are for a transformer that I have missing for some unknown reason. Wires go to inside of my Carrier
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: I have not looked at operation of humidity control on thermostat. There is obviously something not hooked up and I am kicking myself for not taking notes. Not even sure why it was removed If its the transformer
JA: Do you plan on doing the work yourself?
Customer: At this point hopefully yes. I didnt alter anything so I believe I just have to identify the transformer that I need to get
JA: Anything else we should know to help you best?
Customer: WEll, just verifying that this unit came with a transformer for install?