Heater core replacement

Hello,

You will need to drain the coolant and vacuum down the AC system here are two guides to walk you through the repair and instructions and diagrams below to how on your truck below.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

and

https://www.2carpros.com/articles/replace-heater-core

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Here's the skinny on replacing the core. Heater or ac, same procedure. I just did one. Disconnect the battery negative cable. Pull off the plastic dashcover. Do not take all those screws around the opening out. The instrument panel can stay. Remove the plastic lower and center dash covers. Look right under the steering column at the little black cable and the white thumb adjuster. That cable operates the gear indicator, unhook it from the column or you will break it. They're fun to fix too. Take the drivers seat out and sit it back a few inches, seriously, the steering wheel will go all the way to the floor but te seat makes it really tight, best to sit the seat back. Take the two bolts out of the center dash mounting bracket, leave the othe three. 10mm Disconnect the dash main harness and the little one beside it also. Look under the dash and see if any wires have been plastic tied. You might want to cut them loose or they can get pulled loose. You decide. Take the two bottom dash mounting bolts completely out of the sliding thing, dont just loosen them. Take the four nuts off of the steering column and lower it down. Sit the dash over the center bracket and lay it back. Taking loose another wire plug behind the dash. Take the flexible hose loose at the heater box. Take the heater cable off at the box and the vacuum lines apart at the connection. Go under the hood. If equipped with air conditioning, recover the refrigerant. Disconnect the accumulator inlet tubes. Drain the cooling system. Disconnect the heater hoses from the heater core tubes. Remove the four nuts from the heater-A/C mounting studs on the engine compartment side. Hint, one is hid behind the trans fill tube and another one is behind the plastic thing holding the heater hose. Another Hint, you will need a swivel head ratchething wrench 7/16 or 11mm, not a ratchett and socket combo, oh no. Find the vacuum line going inside by the coolant hoses, and disconnect it. Go back inside on passenger side. Remove the mounting brace that secure the heater-A/C housing to dash board. Pull the housing rearward far enough for the mounting studs and evaporator condensate drain tube to clear the dash panel holes. Rotate the box and remove it from the vehicle. Some take them out under the dash, i came out the top, rotating the box clockwise coming up and out. Take the little nut and arm off the flapper. You can leave the push nut alone, but take it off if you can, its easier to put back together. Unplug the vacuum lines from the servos. Be very carefull prying up on the cover, it's very brittle. Lift the heater core out of the housing. Installation is the reverse of removal. Any questions, i'll try.

wigtail@hotmail.com

I had to abandon the attempt to do at a later date.

I put what I believe to be the dash and all electrical connectors back.

(I left some trim pieces off)

The electric is definately on. The dash, lights, airbag, etc. all come on.

However, when I turn the key, I have a clicking sound.

Any ideas?

Is the engine trying to crank at all , or just hearing a clicking noise?

If engine isn't cranking, possible faulty battery, alternator or starter. If engine is cranking, possible faulty relay in the dash. If you can tell that the clicking noise is in the dash, try to feel the relays and see if you can feel any of them clicking. This is the one that needs replacing if that is the case.

I went back out to check the rotation, and it fired right up. Thanks for the quick response.

No clicking now?

Great, glad you have your ride up and running again .

how do i replace the heater core

Actually, this is a very involved process on this truck. If you have AC, you need to evacuate the system. WHat I recommend is to purchase a good repair manual with step by step instructions and pictures to help identify parts. For me to explaine it via the internet allows too much room for error.

I have begun to remove the dash and the heater core hoses but cannot seem to get to the heater core because it is in a black case that also is connected to the AC. Do I have to disconnect the AC to get the houseing that the heater core is in. And take it completly out of the dash to replace the heater core?

Yes discharge AC and entire case must be removed. it houses both evap & heater core

i am try to replace the heater core in my 2000 dodge dakota i have just about all of the stuff unhook ,i have found 3 of the nuts on the outside fire wall i can not fine the 4th one ,i found the one behind the transfill tube also the one behind the plastic clip holding the hose also the one buy the heater core outlet tubes. i am also have trouble disconnect the accumulator inlet tubes. i can not get them to come lose .is there a tool i have to have to get them lose . thanks for any help john morgan

No special tools

To BMRFIXIT , the info you sent me was very helpful i want to thank .i hope i don't run into anymore promble thank you again john

Heater problem
2000 Dodge Dakota 6 cyl Four Wheel Drive Automatic

how to replace heater core at home on this vehicle?

1.Disconnect negative battery cable. Drain cooling system. Remove instrument panel.
2.In engine compartment, disconnect heater hoses and plug all openings. Remove 4 heater assembly nuts from engine compartment firewall. Inside vehicle, remove heater assembly support brace screw, and swing support brace out of way. Move passenger seat rearward.
3.Carefully pull heater assembly rearward until studs and heater core tubes clear firewall. Lower heater assembly. Remove heater assembly from vehicle.
4.Place heater assembly on work bench with assembly housing cover facing down. Remove 2 bolts securing heater assembly housing cover to blower motor housing cover. Unplug vacuum harness connector from panel/defrost door actuator.
5.Remove floor duct from heater assembly housing. Remove 2 bolts securing heater assembly housing cover to lower housing near floor outlet. Turn assembly over. Disengage vacuum harness retainer and vacuum harness. Remove 13 screws securing housing cover.
6.Remove blend-air door lever. Gently pry panel-defrost door lever off. Pull up on heater assembly housing cover far enough to separate cover sealant and remove cover.
7.Ensure blower motor housing cover sealant is in place and in good condition. To complete installation, reverse removal procedure.

Hi,a co-worker of mine has a 2000 dodge dakota 3.9 litre engine,the engine will not warm up or blow heat,the guage just moves off the first line,he has replaced 3 thermostat's a new heater core and just recently a new water pump,other than using c4 to finish the job,what do you think could be the problem,thx Greg

The only thing that comes to mind where I have seen this happen after what you have already done to the truck is the ambient temperature being so cold that the car does not even heat up. Were talking -25 to -35 degrees outside. Even with a block heater and cardboard over the radiator they struggle VERY much to warm up.

The radiator cooling fan being continually on could also cause this situation.

Heater problem
2000 Dodge Dakota Four Wheel Drive Automatic

how long does it take to replace the heater core

Flat rate is around 5 hours. If you have no experience, expect a couple days. Also, the freon will need evacuated from the AC system if you have AC.

I am about to replace the heater core in my 1999 Dakota Sport v6. I am confident in most of the process except for a few things. Is it possible to replace the heater core without messing with the a/c? If so, how does one do so? And if that is not possible, then what is one to do to ensure the a/c will function properly after a heater core replacement?

you can't as you have to pull the heater box out of the truck to disassemble it. i'm including a tip so you don't run into other trouble.

thank you very much for the help. i was reading that something needs to be done with the A/C refrigerant and the evaporator. will this require me to recharge my A/C or anything like that?

yes you'll have to recharge youra/c. If you planon doing this yourself youmight go to a shop who can evacuate the system and ask if theywil recharge it after you are finished . that is to keep the cost down on new freon as they will store yours.

ok so just got everything put together but for some reason one of the things on the outside of the ac/heatercore housing is not functioning. it has two hoses connecting to it. a brown hose and a red hose and they are together side by side and i have tried both positions of the hose how they would fit on the vacuum-like mechanism. it has an arm going from it to the middle of the housing and make one slot open while one closes. it seems like it distinguishes where the air flow goes in the dash but it is not functioning. immediate help would be great i have everything set to go and it is just this little thing that is holding me up. thanks. i have attached an i age to show you which part i am talking about. the hose about it is for climate control with a cable running through it. you can see the two hoses that hook up to it if you look very closely.

that is for your panel/defrost selection i'm sending a chart along. if the actuator is marked red goes to the "f" terminal. it may be hard to see on the thumbnail. make sure you are plugged in an dgetting vacuum to the control switch your main line may be off

how to replace heater core?

WITHOUT AIR CONDITIONING

REMOVAL:
Disconnect the negative battery cable. Drain the coolant.
Remove the steering column cover, intermittent wiper control, if equipped and the lower instrument panel module retaining screw to the right of the steering column.
Remove the center distribution duct retaining screws and panel support screw at the bottom of the module.
Remove the courtesy lamp at the lower right corner of the module and the screw near the ash receiver.
Open the glovebox and remove the screws along the top edge.
Move the module out and down far enough to unclip the wiring harness and antenna cable and disconnect the speaker wire (if equipped with monaural radio) and glovebox light wire. Remove the module from the vehicle.
Remove the center air distribution duct.
Remove the antenna wire from retaining clip at the right end of the heater unit.
Disconnect the blower motor connector and remove the thermal insulator retainer from the heater unit.
Disconnect the demister hoses from the adaptor at the top of the heater unit.
Disconnect the vacuum feed line from the check valve.
Disconnect the temperature control cable flag retainer from the heater unit.
Remove the adjusting clip from the blend air door crank.
Disconnect the heater hoses from the core tubes and plug them.
Remove the four heater unit attaching nuts from the rear engine compartment dash panel.
Remove the heater unit support attaching screw and rotate the brace out of the way.
Remove the heater unit from the vehicle.
To disassemble the housing assembly, vacuum diaphragm and retaining screws from the cover and remove the cover.
Remove the retaining screw from the heater core and remove the core from the housing assembly.


INSTALLATION:
Remove the temperature control door from the unit and clean the unit out with solvent. Lubricate the lower pivot rod and its well and install. Wrap the heater core with foam tape and place it in position. Secure it with its screw.
Assemble the unit, making sure all vacuum tubing is properly routed.
Install the assembly to the vehicle and connect the vacuum harness. Install the nuts to the firewall. Install the support brace to the heater unit.
Connect the demister hoses to the adaptor at the top of the heater unit.
Connect the blower motor connector and install the thermal insulator retainer to the heater unit.
Connect the vacuum feed line to the check valve.
Connect the temperature control cable flag retainer to the heater unit and install the adjusting clip from the blend air door crank.
Install the center air distribution duct.
Install the antenna wire from retaining clip at the right end of the heater unit.
Install the instrument panel module and all related parts.
Connect the heater hoses to the core tubes.
Fill the cooling system.
Connect the negative battery cable and check the heater for proper operation and leakage.



WITH AIR CONDITIONING

REMOVAL:
Disconnect the negative battery cable. Properly discharge the air conditioning system. Drain the coolant.
Remove the steering column cover, intermittent wiper control and the lower instrument panel module retaining screw to the right of the steering column.
Remove the center distribution duct retaining screws and panel support screw at the bottom of the module.
Remove the courtesy lamp at the lower right corner of the module and the screw near the ash receiver.
Open the glovebox and remove the screws along the top edge.
Move the module out and down far enough to unclip the wiring harness and antenna cable and disconnect the speaker wire (if equipped with monaural radio) and glovebox light wire. Remove the module from the vehicle.
Remove the center air distribution duct.
Remove the antenna wire from retaining clip at the right end of the heater unit.
Disconnect the blower motor connector and remove the thermal insulator retainer from the heater unit.
Disconnect the demister hoses from the adaptor at the top of the heater unit.
Disconnect the vacuum harness connector from the air conditioning control hose and vacuum feed line from the check valve.
Disconnect the temperature control cable flag retainer from the heater unit and remove the adjusting clip from the blend air door crank.
Disconnect the heater hoses from the core tubes and plug them.
Remove the condensation drain tube.
Remove the 4 heater/air conditioning unit attaching nuts from the rear engine compartment dash panel.
Remove the heater/air conditioning unit support attaching screw and rotate the brace out of the way.
Remove the heater/air conditioning unit from the vehicle.
To disassemble the housing assembly, vacuum diaphragm and retaining screws from the cover and remove the cover.
Remove the retaining screw from the heater core and remove the core from the housing assembly.


INSTALLATION:
Remove the temperature control door from the unit and clean the unit out with solvent. Lubricate the lower pivot rod and its well and install. Wrap the heater core with foam tape and place it in position. Secure it with its screw.
Assemble the unit, making sure all vacuum tubing is properly routed.
Install the assembly to the vehicle and connect the vacuum harness. Install the nuts to the firewall and install the condensation tube. Install the support brace to the heater/air conditioning unit.
Connect the demister hoses to the adaptor at the top of the heater unit.
Connect the blower motor connector and install the thermal insulator retainer to the heater unit.
Connect the vacuum harness connector to the air conditioning control hose and vacuum feed line to the check valve.
Connect the temperature control cable flag retainer to the heater unit and install the adjusting clip from the blend air door crank.
Install the center air distribution duct.
Install the antenna wire from retaining clip at the right end of the heater unit.
Install the instrument panel module and all related parts.
Connect the heater hoses to the core tubes.
Using new gaskets, install the H-valve and connect the hose connection at the valve.
Evacuate and recharge the air conditioning system.
Fill the cooling system.
Connect the negative battery cable and check the entire climate control system for proper operation and leakage.


Thanks for using 2CarPros.com!

oh make sure the rod going in the hvac unit is connected to.

I have a 1994 Dodge Dakota 3.9L W/ AC. I am in the process of replacing the heater core. I have taken the lower instrument panel completely off, and now I am stuck looking at the heater box, with no idea what to do next. I need to know how to get the box off so I can access the core.

Here are the directions I was able to find for you. Let me know if it helps.

Disconnect the negative battery cable. Properly discharge the air conditioning system. Drain the coolant.
Remove the steering column cover, intermittent wiper control and the lower instrument panel module retaining screw to the right of the steering column.
Remove the center distribution duct retaining screws and panel support screw at the bottom of the module.
Remove the courtesy lamp at the lower right corner of the module and the screw near the ash receiver.
Open the glovebox and remove the screws along the top edge.
Move the module out and down far enough to unclip the wiring harness and antenna cable and disconnect the speaker wire (if equipped with monaural radio) and glovebox light wire. Remove the module from the vehicle.
Remove the center air distribution duct.
Remove the antenna wire from retaining clip at the right end of the heater unit.
Disconnect the blower motor connector and remove the thermal insulator retainer from the heater unit.
Disconnect the demister hoses from the adaptor at the top of the heater unit.
Disconnect the vacuum harness connector from the air conditioning control hose and vacuum feed line from the check valve.
Disconnect the temperature control cable flag retainer from the heater unit and remove the adjusting clip from the blend air door crank.
Disconnect the heater hoses from the core tubes and plug them.
Remove the condensation drain tube.
Remove the 4 heater/air conditioning unit attaching nuts from the rear engine compartment dash panel.
Remove the heater/air conditioning unit support attaching screw and rotate the brace out of the way.
Remove the heater/air conditioning unit from the vehicle.
To disassemble the housing assembly, vacuum diaphragm and retaining screws from the cover and remove the cover.
Remove the retaining screw from the heater core and remove the core from the housing assembly.

I have these instructions already, and I have gotten down to the step where it says "disconnect the blower motor connector and remove the thermal insulator retainer from the heater unit." I don't know where these are located, nor the demister hoses, vacuum harness connector, or really anything else listed there. I don't think that is super important though, my main goal is to find the 4 Heater/Air Conditioning Unit attaching nuts and the heater/AC Support Screw and Bracket so that I can get the actual heater box out. Once i'm past that step, I think I can tackle it. Is there any pictures of this anywhere?

i need to replace my heater core...misting thru the ac vents and pooling fluid in the passenger side floor....can you route me to previous forum descriptions for the repair process so i can review.

Thanks

How to replace heater core and 1996 Dakota, v-6 with air?

EVAPORATOR CORE & HEATER CORE
Removal & Installation (Dakota)
Remove the evaporator/heater assembly. Refer to EVAPORATOR/HEATER ASSEMBLY .
With evaporator/heater assembly removed, remove nut from blend air door shaft. See Fig. 2 . Using pliers, press linkage arm off b lend air door shaft. Disconnect vacuum lines from vacuum actuators.
Remove assembly cover screws from defroster outlet and air inlet openings. See Fig. 2 . Remove remaining screws from top of unit cover. Remove unit cover.
Remove retaining screws, and remove heater core. Remove evaporator core. To install, reverse removal procedure.
EVAPORATOR/HEATER ASSEMBLY
Removal (Dakota)
Disconnect negative battery cable. Remove lower steering column cover. Remove retaining screws from inside ashtray. Remove ashtray assembly.
Remove intermittent wiper control from bracket. Intermittent wiper control is located at lower edge of radio speaker grille, on driver side. Remove instrument panel module retaining screws near right side of steering column.
Remove center air duct located behind lower instrument panel module. Remove support brace screw from instrument panel module. Remove courtesy light at right corner of instrument panel module.
Remove instrument panel module retaining screws above glove box and ashtray areas. Pull instrument panel module rearward and lower it. Secure wiring harness aside.
Disconnect antenna cable from retaining clip on right end of evaporator/heater assembly. Disconnect electrical connector from blower motor. Disconnect defroster hoses at adapter on top of evaporator/heater assembly.
Remove terminal insulator retainer from assembly support brace. Disconnect necessary vacuum hoses. Disconnect Black attaching flag of temperature cable on top of A/C-heater housing, behind defroster tube adapter. See Fig. 3 .
Slip cable self-adjusting clip upward from blend air door crank. Insert a 3/16" (4 mm) diameter rod in crankpin access hole, and rotate self-adjusting clip from cable. See Fig. 3 .
Discharge A/C system using approved refrigerant recovery/recycling equipment. Disconnect refrigerant lines. Plug refrigerant line openings. Drain cooling system. Disconnect heater hoses, and plug heater core tubes.
Disconnect condensation drain tube from fitting on firewall. Remove evaporator/heater assembly-to-firewall retaining nuts. Remove evaporator/heater assembly support brace attaching screw. Swing support brace to left, out of way.
Pull evaporator/heater assembly rearward until attaching studs clear instrument panel and allow assembly to drop down. Rotate evaporator/heater assembly until attaching studs are facing downward. Remove assembly from vehicle.

Heater problem
1999 Dodge Dakota V8 Four Wheel Drive Automatic

need instructions on heater core install

The 2carpros manuals are very easily followed and the job will require the a/c to be evacuated, recycled, and recharged.
It is about a 6 hour job start to finish with air, and power tools.

hello i hope someone could help me. I have a 99 dakota and my heat doesnt work my father in law has a friend mechanic said he would replcae my heater core for 350.00 including parts. should i let him do it or try it myself i am pretty good at taking things apart and putting them back together. however i dont have the money right now to get the job done. In the meantime what can i do for heat I bought a little heater from walmart it plugs in to the auxiliary, but i dont have one alls i have is a ciggarette lighter to pug it in and that of course blows the 15 ampfuze i need 20 or higher. what im trying to ask is can i somehow connect this heater to the battery and would that be a dumb idea or could i use the orange dimmer wire behind the radio and just ground it to the chassis. its been very cold in nj lately

First, replacing the heater core is a huge job on this vehicle, expecially if the vehicle has AC. His bid or 350 for parts and labor is a good deal. But I know the feeling. If you don't have it, the price may as well be 100,000. Are you sure the heater core is bad? If so, how have you checked?

As far as the heater you purchased, don't splice into anything. Most every electrical component runs through some type of a computer. If you start playing around with it, you'll cause other problems.

If you know how to power if from the battery, that will work. However, make sure to run an inline fuse to the heater so it blows the fuse if there is a short and doesn't start a fire.

Let me know if you have other questions.

Joe