Ill try to keep it fairly short. Im $2000.00 in the hole on my rear air in a 1997 sub. The guy said he replaced everything and he finally thought he had it figured out , said it was the tempcontrol valve under the hood, he replaced that the air works fine and now the heater in the back doesnt work. Anyway, to get some pics or diagrams of the two heater control valves for the front and the back, my Chiltons book doesnt show it. I think he messed up my vacum setup, because only the drivers control works both valves. The heat and the air both work fine in the front. the back only has air. Any help would be greatly appreciated. WI winters are cold need to get it fixed. Thanks!