Hey, Rob321. My sc400 is also having heat problems. Dealer told me it could be a problem with the heater control valve.
My question to you: Is the heater control valve the same thing as the water vacuum solenoid valve?
Here's a picture of mine
http://lh5.ggpht.com/_AcSRZQZTpeU/TPMFRfy4wWI/AAAAAAAAA9w/iaPcFtmUcSE/s800/100_0457.JPG
If this is the part you are talking about, are you saying to take the tube from the top circular area and switch it where?
As much details as possible would be helpful.
and Any help is appreciated.
