Oops, I'll have to check what it says on the dash for my controls. Also, there was a 3rd duct for the defroster. Whatever rate the coolant was running through the front heat would be the same in the back because the hoses for the rear core came off the same valve assembly as the front. I believe, from the top, the label next to the rear control toggle switch it says "defrost", "air", and "heat". I think there is also a toggle for the fan. And I think that is "High", "Low", "Off". Anyhoo, I'll check when I get home. Dave 67 Haze Green Sedan Covington, Wa.