I have a 1993 Ford f250 and just replaced my heater core by just taking out the glove box. I believe it is the same on an 88, although it is a little tight. Once you take the glove box out there should be a black cover over the heater core, just remove that. Next open the hood and disconnect the two hoses going into the heater core. Now the heater core should just pull out. Do the same in reverse to put the new one in It is pretty simple, but in some cases you may have to take the dashboard off, which is a pain. Pretty sure on an 88 f250 you be able to go it through the glove box.
Remove the center console remove the floor vent remove the heater core cover the heater core is right under the climate control unit remove the two screws that hold the heater core in place, open the hood and remove the heater hose from the heater core lines, now go inside and pull out the old heater core you don't have to remove the whole dash just the front of it
comes out inside . remove glovebox and go in that way . about one hour .
Disconnect the heater hose off the heater core on the firewall and remove the inside middle side panels along with the lower heater core panel and pull the core straight out.........
The heater core is inside of the car. It is under the dash on the passenger side, and it is in a box that has to be unbolted from the das to remove the core.
remove the four nuts in the engine bay on the heater box near where the heater core hoses enter. Drain coolant remove the hoses and pull the heater box out from the inside of the car. Remove clips holding heater core, than put your new one in.
After you remove the hoses from the core, remove the nuts and bolts that secure the heater case to the firewall in the engine bay. Inside the cab you will have to remove the glove box assembly for clearance. then disconnect the blower fan wiring. there may be another bolt securing the heater case to the firewall on the inside of the cab. Then you should be able to remove the heater case. You'll have to split the heater case to get to the core.
Heater core is located inside the H/AC "suitcase". It can be a chore, but you're best bet is to remove the 'suitcase' and remove the heater core once the suitcase is on the ground.
Chilton's says to remove hoses from the 2 connectors inside engine compartment and remove the dash panel and lower panel. Then reach inside and pull the heater core out.
# Disconnect the negative battery cable and drain the cooling system. # Disconnect the heater hoses from the heater core inlet and outlet connections in the engine compartment. # Allowing residual coolant from the heater core to drain. Cap the openings. # Working inside the vehicle, remove the lower instrument panel sound insulator. # Remove the heater floor outlet duct screws or clips and remove the duct. # Remove the heater core cover by removing the attaching screws and clips. # Remove the heater core cover. # Remove the heater core retainers and remove the heater core.
drain coolant. remove heater hoseson the inlet and outlets inside engine compartment passenger side near firewall.remove heater core pipe clamp.remove the glove box.remove insulation below it.remove the evaporator temp sensor wiring clip from the heater core cover. remove heater core cover. remove core clamp then slide the core out carefully.
Remove glove box door. Behind that is heater core. Remove the cover,the core is right there. Under the hood, against the firewall you'll see the hoses going to the core. Remove 2 hose clamps then the core will come out from from the inside of your truck.
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