Hello. 6 years ago, my contractor installed an Aprilaire 600 with automatic humidstat in my 3600 (including basement) square foot house. The 600 is set to turn on when there is a heat call from the thermostat. We feel that we are not getting enough humidity possibly because the heat does not run enough to provide all the humidity that the humdistat would call for.
Aprilaire suggested we install part 4851 that enables the humidistat to call for fan on if humidity is required regardless of heat call. There are 5 wires on the 4851. I can easily connect 2 of them to the humidistat, but the other 3 need to go to my heat pump air handler Model ARUF042-00A-1 (I think Goodman).
Aprilaire told me how to connect the wires, but I can't find wire screw panels, only thick red blue white brown wires coming out of the top of the air handler. Considering the part only costs $30, I would hate to pay my contractor a total of $170. Aprilaire told me that the contractor could do it in their sleep.
Any help/advice would be appreciated on how to connect this thing.