Big job, and if it has ac it's even a bigger job. I would suggest purchasing a shop manual for that vehicle if you intend on doing this job yourself. There are to many steps to list here.
Yes.
Open both front doors and remove everything from the front seat to the firewall, no kidding.
Yes.
Remove the water supply hoses from your 1992 Chevy S 10 pickup truck heater core. Remove the heater core retaining bolts. Reverse the process to install your new heater core.
Drain the water from your 1994 Chevrolet Blazer cooling system. Remove the heater core water supply hoses. Remove the heater core retaining bolts. Reverse the process to install the new heater core.
The heater core comes out from the inside. If you have air it is a little harder. Remove the dash bolts it does not need to come all the way out. also remove the glove box this will help you remove the heater box which the heater core is behind pretty easy after the dash is out of the way hope this helps
What are the steps to change the heater core on a 1991Chevy S10 pickup ?
Open up both front doors and remove everything from the front seat to the firewall, no kidding.
i have a 93 s10 blazer and had to replace the heater core recently, it is a pain, and it helps to have another person there to give you a hand, you have to take the entire dash out, remove the heater core cover, undo the brackets and undo the hoses from the heater core, the worst part is removing the dash and remembering where all the wires go if you do this job yourself i sugest taking pictures as you go along
You need to remove instrument cluster. And the whole dash to access heater box. The heater box case has to be slpit in half to access heater core. A very timely and frustrating job. Take to a professional is what I recommend.
A replacement heater core would cost aprox $35.
The only access to the heater core on a 96 S10 blazer is by removing the entire dash asm. It is not accessible from the engine compartment. If you are not familiar with disabling the the air bag system, do not attempt this repair.