Location of heater assembly fire wall bolts and how to remove heater core on my 1993 YJ Wrangler?

bypass the heater core. 2 small hoses run from the firewall to different locations on the engine (one should be the thermostat housing. dissconnect one hose from fire wall end, and reconnect it to where the opposite end of the other hose is located, creating a loop that does not include the heater core. The remaining hose (one end still attached to the heater core at the fire wall) should be connected to the opposite connection at the fire wall so it can be re-engaged next winter.

Actual problem seems to be the heat damper valve, which restricts water flow into the heater core, easiest fix is reattach the actuating cable to the valve arm (if this was detached) most costly is replace valve assemble/heater core assembly....

ok, so you know where it is nor not?
its in the heater box.
and the box is in the dash
so, the box needs to be removed.
then box split (screws)
then replaced,
the FSM covers this,
ive posted this over 100 times here.
again.
YJ, the real deal. real jeep book;
yj 93 is here for free, they are same.
heating and air. cond.... yes HVAC.

http://www.morris4x4center.com/knowledge-base/index.htm?utm_source=cj#service


pdf page 41 of 51
starts there.... every word.
clear.

Hi and welcome to FixYa!

It may take 2hours the most to replace the heater core.

Hope this helps and thank you for using Fixya! Have a good one!

Heater Core REMOVAL & INSTALLATION 1985-95 Models For the removal of the heater core, which is located inside the heater-A/C unit assembly, first remove the heater-A/C unit assembly from the vehicle as described later in this section. Once the unit has been removed, use the following procedure to extract the heater core:

1. Place the heater-A/C unit on a suitable work surface.
2. Locate and remove one retaining nut from the blend-air door pivot shaft.
3. To remove the top cover from the heater-A/C case, the crank arm must be removed.
4. Disconnect the vacuum lines from the defroster and panel mode vacuum actuators and position them out of the way.
5. Remove the 3 heater-A/C unit cover attaching screws, fastened upward at the defroster outlet chamber.
6. Remove the 2 heater-A/C unit cover attaching screws, fastened upward at the air inlet plenum.
7. Remove the 11 heater-A/C unit cover attaching screws, fastened downward into the housing. Then lift the cover from the heater-A/C unit.
8. Remove the old heater core from the case. To install:
   
9. Install the new heater core into the heater-A/C unit case in the same position as the old one.
10. Place the cover onto the case and secure in place with the 11 retaining screws.
11. Install the remaining components in the reverse of the removal procedure.
12. Install the heater-A/C unit assembly into the vehicle.

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1989-95 Models EXCEPT DYNASTY AND PREMIER NOTE: The following procedure can be used on all specified 1989-95 models. Slight variations may occur due to extra connections, etc., but the basic procedure should cover all models. Modify the service steps as necessary. Refer to the supplemental restraint system disarming procedure as necessary. NOTE: It is vital to have the A/C system discharged by a reputable automotive technician utilizing a recovery/recycling machine before detaching the A/C system. Refer to the A/C system precautions presented in Section 1.

1. If the vehicle is equipped with air conditioning, have the A/C system discharged by a qualified professional mechanic, using an approved recovery/recycling machine.
2. Disconnect the negative battery cable. Drain the cooling system.
3. Clamp off the heater hoses near the heater core and remove the hoses from the core tubes. Plug the hose ends and the core tubes to prevent spillage of coolant.
4. Disconnect the H-valve connection at the valve and remove the H-valve. Remove the condensation tube.
5. Remove the glove box, right side kick and sill panels, and all modules, relay panels and computer components in the vicinity of the heater housing.
6. Remove the lower instrument panel silencers and reinforcements. Remove the radio and other dashboard-mounted optional equipment, as required.
7. Remove the floor console, if equipped. Remove the floor and defroster distribution ducts.
8. Remove the bolt holding the right side instrument panel to the right cowl.
9. Disconnect the blower motor wiring, antenna, resistor wiring and the temperature control cable.
10. On 1990-95 Daytona and LeBaron models, using a suitable cutting device, cut the instrument panel along the indented line on the padded cover to the right of the glove box opening. Cut only plastic, not metal. Remove the reinforcement and the piece of instrument panel that is riveted to it.
11. Disconnect the demister hoses from the top of the housing, if equipped.
12. Disconnect the hanger strap from the package and rotate it aside.
13. Remove the retaining nuts from the package mounting studs at the fire wall.
14. Fold the carpeting and insulation back to provide a little more working room and to prevent spillage from staining the carpeting. Pull the right side of the instrument panel out as far as possible.
15. Remove the heater housing from the dash panel and remove it from the passenger compartment. If the passenger seat is preventing removal, remove it.
16. To disassemble the housing assembly, remove the retaining screws from the cover and remove the cover.
17. Remove the retaining screw from the heater core and remove the core from the housing assembly. To install:
    
18. Remove the temperature control door from the housing and clean the unit out with solvent. Lubricate the lower pivot rod and its well, then install. Wrap the heater core with foam tape and place it in position. Secure it with its screw.
19. Assemble the housing, making sure all cover screws were used.
20. Connect the demister hoses. Install the nuts to the fire wall and connect the hanger strap inside the passenger compartment.
21. Fold the carpeting back into position.
22. Install the bolt that attaches the right side of the instrument panel to the cowl.
23. Connect the blower motor wiring, antenna, resistor wiring and the temperature control cable.
24. Install the remaining components in the reverse of the removal procedure.
25. Fill the cooling system.
26. Connect the negative battery cable and check the entire climate control system for proper operation and leakage.
27. Have the air conditioning system evacuated and recharged by a qualified professional mechanic utilizing the proper equipment.

Hello. Remove air cleaner and duct assembly. Drain coolant. Remove both heater hoses at the heater core. Remove right and left instrument panel sound insulators. Remove rear compartment heat duct adapter bolt/screw and adapter. Remove heater outlet duct bolts and duct. Remove heater core cover. Remove heater core.

There is a drain tube on the lower part of the firewall that is probably plugged.Normally I use a pick to dislodge debris some use coat hangers but you must be careful not to poke at too hard and cause a freon leak in the evaporator core.

Their will be 4 or 5 bolts holding the housing to the fire wall that you have to get to from the engine compartment and maybe one of the housing that has a ground wire on it.

Heater Core 1. Disconnect the battery ground cable 2. Drain the engine coolant. 3. Remove the instrumental panel. 4. If equipped with the 5.4L 4V engine, remove the junction block splash shield. 5. If equipped with the 5.4L 4V engine, remove the bolts and disconnect the cable ends from the starter relay. 6. If equipped with the 5.4L 4V engine, remove the junction block bracket. 7. Disconnect the heater core hose couplings. 8. Remove the retaining screw and remove the A/C plenum demister adapter. 9. Disconnect the vacuum line from the A/C plenum demister adapter. 10. Remove the heater core bracket. 11. Remove the 13 plenum chamber top retaining screws. 12. Remove the plenum chamber top. 13. Remove the blend door assembly from the case. 14. Remove the heater core. 15. The installation is the reverse of the removal.
The heater core should be encased in a box up inside the dash.The best way to find this is to locate the heater hoses that go through the fire wall(about 1 1/4 in diameter).This is a very tight job and you will spend most of you time laying on the floor taking out screws.Be careful not to loose any of the heater core casing screws or bolts and when refilling the coolant system fill the radiator directly,start the engine with the radiator cap off,the level will drop,fill the radiator the rest of the way and replace the cap,allow the engine to reach normal operating temp.(about 10 to 15 minutes)so that the themostat will open and then allow the engine to cool and recheck fluid level.

heater core under dash passenger side . Remove 2 hoses on fire wall carefully then take cover off the heater box & remove heater core. be careful not always an easy job!

I have a 1993 Jeep Wrangler YJ...My heater core needed replacement when I bought it about a year ago. I made the mistake of taking apart the dash to get to the heater core. DO NOT DO THIS!!! It is actually 4 screws that you must take out from the inside of the engine compartment on the firewall. Then it will come right out. Have fun!!!