Installed n aprilaire 500M automatic whole house humidifier. But then I realized I have a thermostat that can control humidity (TPCM32U04A) but oh well. When I went to wire it up I got a little lost. Inside my 5 series there is not a normal thermostat hookup like I have delt with before. I need a 24v power source, would R and C going to thermostat work? The thermostat only has 4 wires hooked to it. R C A+ B- What would I attach to get an ON signal to the humidistat? I believe I only want it to come on when the blower and heat are on? Any ides how I should wire this thing?