My heating core is OK (the IN and OUT hoses are hot, no leaks either) but when sliding the lever to either HOT or Cold, it always blows cold air. I was able to partially disassemble the heat/AC control unit and saw that the cables are moving. I also traced the cable to the other end (right behind the glove box) and saw that it moves another lever but from then ON I can see anything. I am guessing that the flaps directing the hot air are malfunctioning but how do I get to them? I can pull the glove box down but all I see is a black plastic wall with not visible way to get through. Any ideas are much appreciated.

Now that I looked more closely the house going in the heating core is hot but the one coming out is NOT. The heating core deas not leak but what could that be..., maybe it is plugged - if you have an idea, please share. Thanks

OK...., here is the latest: I was able to get to heater core and it was pretty easy - just pull the soft cover below the glove compartment and you will see a black somewat rounded bottom cover of a plastic square box which you can remove with 4 screws and the heater core will show up. However, my heater core never gets hot. I am guessing that it is plugged or something like that. How can flush it or unplug it? I think removing it is ver hard although you can see most of it if look up under the glove compartment once that cover with the 4 screws is removed.

Well..., day by day I try different things and here is the answer to my original question. As it sounds dump to answer my own questions, at the same time you can all benefit from my own replies. The problem was that my heating core was clogged and water was not circulating through it, therefore it always stayed cold. To my surprise getting to it and pulling it out was very easy. How to get to it is described above and her is hot to pull it out: just detach both houses found under the hood next to the firewall (the IN and OUT one) which is the only thing that keeps the heater core stuck next to the firewall. Once you remove the houses you can simply push in the two aluminum outlets which will detach it. You can then reach from beneath the glove compartment to pull it out. I flushed mine with a regular hose by circulating water in the opposite direction of the flow of coolant went it is installed in the vehicle. At first I had to apply pressure by using the jet setting on the house and a bunch of rusty water cam out. I then flushed it in the opposite direction until clear water was coming out. That is it, worked like a charm – good luck.

Well..., day by day I try different things and here is the answer to my original question. As it sounds dump to answer my own questions, at the same time you can all benefit from my own replies. The problem was that my heating core was clogged and water was not circulating through it, therefore it always stayed cold. To my surprise getting to it and pulling it out was very easy. How to get to it is described above and her is hot to pull it out: just detach both houses found under the hood next to the firewall (the IN and OUT one) which is the only thing that keeps the heater core stuck next to the firewall. Once you remove the houses you can simply push in the two aluminum outlets which will detach it. You can then reach from beneath the glove compartment to pull it out. I flushed mine with a regular hose by circulating water in the opposite direction of the flow of coolant went it is installed in the vehicle. At first I had to apply pressure by using the jet setting on the house and a bunch of rusty water cam out. I then flushed it in the opposite direction until clear water was coming out. That is it, worked like a charm – good luck.

That's the same thing I had to do when I replaced the engine in my '92 Ranger XLT.