It is located behind the dash, inside the HVAC assembly. This is a fairly complicated job, even more difficult if it has AC. I would recommend a shop manual for that vehicle if you want to DIY.
you have to take the dash easyout to get to the heater core box . Its a two man job and is not easy.
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.
$400 to $600 depending if it has ac or not.
Disassemble the dash and open up the HVAC compartment.
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.
Check your heater core and thermostat. The thermostat may be stuck open. Does the S10 run hot or cold?
Heater core changed three years ago,I changed Thermostat Heater still blows cool air.
What are the steps to change the heater core on a 1991Chevy S10 pickup ?
Recommend you buy a Chilton or Haynes manual for this one. Explaining it without visual references makes it a bit more difficult. Before you go through the process of changing out the heater core, try backflushing it to see if it might simply be clogged.
A blockage in the heater core is the most likely cause. This is a difficult and expensive repair.
Probably around $500 or more if you have AC.