Hello everyone, so I've been fiddling around with my 84' trying to square away all the problems I inherited when I bought it a few years ago. This episode surrounds the interior heating problems I've been having. Blower works, position, speed, recurring and fresh work, and the air direction work. The problem is that no heat from the coolant is being blown through (only heat I get is during the summer months) I've gone through a few possible culprits in attempt to fix the problem, I used a garden hose to force water through the coolant hoses to check if the heater core is clogged, I lubed the heater valve because it felt stiff when moving it and I manually open the valve using a hand vacuum pump, to which I do feel hot coolant flow through so I know its moving somewhere (I also think the vacuum valve things next to the washer fluid tank are a possible culprit). All have yet to provide hot air, so I took the dash out because the only other thing that my mind thinks can be the problem, is the heater core, or the climate control unit, my pops suggests its the unit, but before I spend more money on parts that may not fix my problem, I figured asking the sages of the Celica Supra forums before I do anything else. Help?