Search:

You still won't loose more than a quart of fluid, which if you want you could recover first

Well, really I think you should just disconnect those hoses. When was the last time you changed fluid anyway? If you loose a little at the top, not a biggie

Sure, why not

You can check the heater core by disconnecting the lines and shoving a hose to one and see if you get water out the other

OK, I think the problem is the blend door. It is mechanically operated by the nob on the dash. If I was going to chase this down, I would start with removing the covering and accessing the...

One more question. When you operate the selector to heat, AC etc where does the air come out. Defrost vents?

This might be a stupid question, but have you checked the level of coolant in the radiator? When they get down a little you will loose coolant circulation in the core