How do you replace heater core in S10 Chevrolet?
you have to take the dash out.it's a big project.
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 am pretty sure it is right above passenger side floorboard, up in dash. I have changed heater cores in Ford vehicles, and all of them were above floorboard on passenger side. Locate the heater core, and it should have water lines running into and out of the core. Use wrench, and take lines off of core, buy new core, and replace lines into new core.