Does anybody have a schematic of the car's cooling system, with the sensors, the pumps, heater matrix and aux heater? If the aux heater is connected in line with the rear blower, I guess there's a pump that's not 100% working, or that the pipes are clogged. From what I can find, all the piping for the rear heater and aux heater is connected to the main cooling circuit via t-connectors, and that rear in the engine bay there's also an electrical pump for this circuit. Also it seems the aux heater is in line with the rear blower. So since my heater is overheating, it seems maybe there's not enough cooling liquid flowing in that circuit. The pump that has a plastic wheel connected to a steel rod that tends to fail, is that the electrical pump I'm talking about above, or the main waterpump? Any thoughts?