I just got a 1999 Ford conversion. I was having a no heat problem in the back but the ac worked fine. I opened the bow and found out that he had removed the heater core. I got in touch with ACC Climate Control and they all of the parts you need for that rear unit. They are the ones who distribute it. I do have a question for you though. Where did you find that vacuum valve that turn off the hot water to the rear unit when you're running the ac. I want to make sure it's good. ACC Climate said that it's a ford part but as you know it can be hard to get under there to find it and was it hard to replace?