You need to go to a car parts store, and get a repair manual for your car. They cost about $16.00 Or, go to a Public Library.
you have to take the dash easyout to get to the heater core box . Its a two man job and is not easy.
Disassemble the dash and open up the HVAC compartment.
What are the steps to change the heater core on a 1991Chevy S10 pickup ?
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.
The entire dash assembly needs to be removed to gain access to the heater core. If you want to do this job I would recomend purchasing a shop manual for that vehicle to help walk you thru it.
Open both front doors and remove everything from the firewall to the front seat. No joke.
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.
A blockage in the heater core is the most likely cause. This is a difficult and expensive repair.