I have 95 blazer, 4wd. There is water leaking from under the dash. The defrost will not work and the windows are steaming up. When I say water I mean there is a bath towel under there that is saturated.

 

Sounds like the heater core has failed and is leaking.

 

So, is this something I can do?

 

If you do it it will require allot of patience. You will have to effectivley strip the dash. Layer after layer. It is no small job. Take plenty of pictures and make notes. When you get to where you can remove the core your truck will look like it came out of a junk yard. I'm not trying to scare you. Just trying to impress upon you how involved it is. It took me an entire weekend. But then again I'm old and slow. If you have any doubts, have someone else do it. If you are a confident mechanic; get a factory service manual and go for it. Good luck.

 

I am not sure if the dash is set up like a 96, but if it is, it was pretty straight forward. If you have a chilton's manual, even though they aren't the best, it will get you through it. I did mine in about two hours. I agree that its your heater core.