To preface my post, I have taken the vacuum lines off the solenoid, moved the plunger myself, and also checked the coolant level. Taking the vacuum lines off only allowed me to move the plunger. Moving the plunger didn't do anything (still no heat). And the coolant is in check.

So I started looking around and there are two "spare" hoses back there. Big ones. Like, coolant hoses. I'll let the pics explain:

Apparently someone installed a bypass which goes from here:


To here:


The only reason this would have been installed that my dad and I can think of is because the heater core was leaking. Is it common for the heater cores to leak inside the cabin? I'm tempted to hook it up like it was originally and see if I get heat back.

Any thoughts?

Oh, the bypass hose is orange, but it shows up white in the pics. You can see the orange in the second pic but it looks white in the first pic.

PS: I posted this in the performance section but received zero replies. I'd like heat ASAP and I think that no antifreeze going through what appears to be the heater core is the problem. I think that is the heater core but I'm not sure. I've only owned the car for 3 days and I don't have the shop manual.