I'm assuming then you have auto air. And yes there was some kind of color code to the lines but it seems like there were quite a few white ones. I think the number one problem was in the 2 lines that went to the vacuum canister. One operated your vacuum controlled heater valve (the manual air had a cable operated valve)that defaults to the full heat position. The other hose operated the vents and doors and went thru that vacuum octopus.
There is a multitude of sensors...one in top of your dash (that is the buzzing you hear) which somehow measure temp of the cabin air, there is one in the bumper next to the right turn signal to measure outside air. A few others who probably have dirty contacts.
You will not know if it works properly until you get it back together. When working, the fan will slow down the closer you get to your desired temperature. Sometimes that recirc push switch is dirty and will not open the recirc door. You must remove the switch, drill out the 2 small rivets, and clean the points inside. I reassembled using cotter pins bent backward.