Sorry for the triple post, but haven't had time to take the wheel off so for now I'm not gonna paint the rim. However, me and my dad were looking around in the engine bay and found out what that hanging tube goes to. It goes straight into the engine where the antifreeze goes into and there's a hose there that's looped from the left side of the engine that's supposed to go into the heater control valve. So, we did a quick switcheroo, leaked some antifreeze, cleaned antifreeze off, and tried to run the heater. Apparently, the tube that comes out of the firewall directly into the rear end of the heater control valve isn't on tight enough, and that's probably why the previous owner bypassed the heater altogether. However, we can't get to the tube because it's in the most uncomfortable, most inaccessible position behind the intake, under ten more hoses. (Exag.)
This picture is the tube that goes into the engine, and the tube pictured on the right (meshed) goes to the heater control valve.