removal of heater hose from engine to fire wall
replace heater core in a 1991 Chevy work truck 1500
Begin by removing the water supply hoses from your 1989 Chevy heater core. Remove the heater core retaining bolts. The heater core can be removed.
$400 to $600 depending if it has ac or not.
Bad heater core.
It is located on the firewall right behind carborator.
It is located under the AC and Heat instrument panel
If the heater core is ok, check to insure your ac unit is working. The ac works in conjunction with the heat when running defrost, and without the ac air windows will fog up .
Check your fuses!
beside the brake booster on the firewall, under the AC lines (if equipped)
Parts and labor, $500 to $600 without AC. With AC, $600 to $700. It really depends where you live also.
Unfortunately the entire dash must come out to replace that unit.
Probably around $500 or more if you have AC.