Heater Core Replacement

Never replaced the heater core on a modern Mustang, but on my classic I can tell you it was the biggest PITA I've ever seen.

If it's a small leak, maybe disconnect the inlet and outlet hoses and connect them with one of those drill-operated pumps, and then circulate some water through the core with some of that leak stopper added. I wouldn't just add it to your whole system, since it will cause early failure of your radiator, but to fix your heater core it might do the trick. It beats having to pull the darn thing out of your dash!

THIS IS FUNNY

my very first visit to STANGNET was for heatercore..........yes on this site you will find your answer with a clear pitcure and i still havent done it 3yrs later...all i can pass on to you is fords step by step,,with air bags now its harder than before with out a face full of bag,,,,,,lol good luck

hotcobra03 said:

my very first visit to STANGNET was for heatercore..........yes on this site you will find your answer with a clear pitcure and i still havent done it 3yrs later...all i can pass on to you is fords step by step,,with air bags now its harder than before with out a face full of bag,,,,,,lol good luck

Click to expand...

Did the airbag give you a good TKO ehh?

That's why you always disconnenct the battery and wait a couple minutes before working around those things.Damn cores ARE a PITA because they are packed so far up into the firewall behind the dashboard.I hope I never have to do one. Good luck tho.Sorry I couldn't be of much assistance...................oh yeah,get a Haynes manual.They are a BIG help.

I have a 96 with nearly 150K miles.So far no core problems.

face full of bag

MustangLX-5.0 said:

Did the airbag give you a good TKO ehh?

That's why you always disconnenct the battery and wait a couple minutes before working around those things.Damn cores ARE a PITA because they are packed so far up into the firewall behind the dashboard.I hope I never have to do one. Good luck tho.Sorry I couldn't be of much assistance...................oh yeah,get a Haynes manual.They are a BIG help.

I have a 96 with nearly 150K miles.So far no core problems.

Click to expand...

i have a ford manual and just un-hooking the battery isnt all the steps.air bag will still blow says ford...inside of left front fender is a connection that has to be un pluged to dis-arm bags... i will post the steps ,ford says its a 15 hour repair with 2 techs.

its a pita but dash has to come out...on this site i did fiind a pic of cutting air box to remove core and than you patch the hole when done,,,,SECTION 501-12: Instrument Panel and Console 2003 Mustang Workshop Manual
REMOVAL AND INSTALLATION Procedure revision date: 03/18/2002

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Instrument Panel Printable View (718 KB)
Removal

CAUTION: Electronic modules are sensitive to static electrical charges. If exposed to these charges, damage may result.

Remove the driver air bag module. For additional information, refer to Section 501-20B .
Remove the passenger air bag module. For additional information, refer to Section 501-20B .
Remove the LH front wheel and tire assembly. For additional information, refer to Section 204-04 .
Position the LH fender splash shield away from the dash panel.
Remove the pin-type retainers.
Remove the screws.
Position the LH fender splash shield away from the dash panel.

Disconnect the bulkhead electrical connector from inside the fender opening.
Loosen the bolt.
Disconnect the bulkhead electrical connector.

Release the bulkhead electrical connector from the dash panel.

Install the LH front wheel and tire assembly. For additional information, refer to Section 204-04 .
Remove the floor console. For additional information, refer to Floor Console in this section.
Remove the upper RH instrument panel support bolt.

Disconnect the antenna in-line connector.

Disconnect the climate control vacuum harness connector.

Close the glove compartment.
Remove the LH and RH scuff plates.

Remove the LH and RH A-pillar lower trim panels.
Remove the pin-type retainers.
Remove the A-pillar lower trim panels.

Remove the LH and RH windshield side garnish mouldings.
If equipped with a convertible top, remove the pin-type retainers.

Position the LH and RH door weatherstrips aside.
Disconnect the RH main wiring harness electrical connectors.

Disconnect the climate control wiring harness connector.

Remove the instrument panel steering column cover.
Remove the screws.
Remove the instrument panel steering column cover.

Remove the instrument panel reinforcement.
Remove the screws.
Remove the instrument panel reinforcement.

Separate the intermediate shaft from the steering column shaft.
Remove the pinch bolt.
Separate the intermediate shaft from the steering column shaft.

NOTE: The corner of the carpet may have to be pulled back slightly to carry out this step.

Disconnect the LH main wiring harness electrical connectors.

Disconnect the generic electronic module (GEM) electrical connectors.

Disconnect the electronic crash sensor (ECS) module electrical connector.
Release the locking tab.
Disconnect the ECS module electrical connector.

If equipped, disconnect the shift interlock assembly from the selector lever.
Remove the screw.
Remove the R-clip.
Disconnect the shift interlock cable.
Disconnect the shift interlock assembly from the selector lever.

Remove the audio unit. For additional information, refer to Section 415-01 .
If equipped, disconnect the shifter assembly electrical connector.

NOTE: This step is being carried out through the audio unit opening.

NOTE: Rotate the temperature control switch to the cool position.

Release the temperature control cable from the blend door.

Remove the four center instrument panel support bolts.

Remove the LH instrument panel support bolt and nut.

Remove the RH instrument panel support bolt.

Remove the instrument panel defroster grille.

Remove upper instrument panel support bolts.

NOTE: Two technicians are necessary to carry out this step.

Remove the instrument panel.
Installation

CAUTION: Electronic modules are sensitive to static electrical charges. If exposed to these charges, damage may result.

NOTE: Two technicians are necessary to carry out this step.

Install the instrument panel.
Install the upper instrument panel support bolts.

Install the instrument panel defroster grille.

Install the RH instrument panel support bolt.

Install the LH instrument panel support bolt and nut.

Install the four center instrument panel support bolts.

NOTE: This step is being carried out through the audio unit opening.

Install the temperature control cable to the blend door.

If equipped, connect the shifter assembly electrical connector.

Install the audio unit. For additional information, refer to Section 415-01 .
If equipped, connect the shift interlock assembly to the selector lever.
Position the shift interlock assembly.
Connect the shift interlock cable.
Install the R-clip.
Install the screw.

Connect the ECS module electrical connector.
Connect the ECS module electrical connector.
Engage the locking tab.

Connect the GEM electrical connectors.

Connect the LH main wiring harness electrical connectors.

Connect the intermediate shaft to the steering column.
Connect the intermediate shaft to the steering column.
Install the pinch bolt.

Install the instrument panel reinforcement.
Position the instrument panel reinforcement.
Install the screws.

Install the instrument panel steering column cover.
Position the instrument panel steering column cover.
Install the screws.

Connect climate control wiring harness connector.

Connect the RH main harness electrical connectors.

Install the LH and RH door weatherstrips.
Install the LH and RH windshield side garnish mouldings.
If equipped with a convertible top, install the pin-type retainers.

Install the LH and RH A-pillar lower trim panels.
Position the LH and RH A-pillar lower trim panels.
Install the pin-type retainers.

Install the LH and RH scuff plates.

Open the glove compartment.
Connect the antenna in-line connector.

Install the upper RH instrument panel support bolt.

Connect the climate control vacuum harness connector.

Install the floor console. For additional information, refer to Floor Console in this section.
Remove the LH front wheel and tire assembly. For additional information, refer to Section 204-04 .
Insert the bulkhead electrical connector into the dash panel.

Connect the bulkhead electrical connector.
Connect the bulkhead electrical connector.
Tighten the bolt.

Install the LH front splash shield.
Position the LH front splash shield.
Install the screws.
Install the pin-type retainers.

Install the LH front wheel and tire assembly. For additional information, refer to Section 204-04 .
Install the passenger air bag module. For additional information, refer to Section 501-20B .
Install the driver air bag module. For additional information, refer to Section 501-20B .


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SECTION 412-02: Heating and Ventilation 2003 Mustang Workshop Manual
REMOVAL AND INSTALLATION Procedure revision date: 03/18/2002

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Evaporator Core Housing Printable View (225 KB)

Material Item Specification
PAG Compressor Oil (R-134a Systems)
F7AZ-19589-DA (Motorcraft YN-12-C) WSH-M1C231-B
MERPOL®
NA ESE-M99B144-B

Removal

NOTE: The evaporator core is not separately serviceable, it is serviced only with the evaporator core housing assembly.

Disconnect the battery ground cable.
Recover the refrigerant. For additional information, refer to Section 412-00 .
Drain the cooling system. For additional information, refer to Section 303-03A or Section 303-03B .
Remove the instrument panel. For additional information, refer to Section 501-12 .
Disconnect the heater hose couplings from the heater core. For additional information, refer to Section 412-00 .

Disconnect the vacuum connector.

Remove the suction accumulator/drier. For additional information, refer to Section 412-03 .
Disconnect the A/C liquid line.
Discard the O-ring seals.

Remove the evaporator core housing nuts.

Remove the nut.

Remove the screw.

Remove the interior evaporator core housing bolts.

Remove the evaporator core housing.
Installation

To install, reverse the removal procedure.
Lubricate the coolant hoses with coolant hose lubricant or plain water only, if needed.
Install new O-ring seals lubricated with PAG oil.



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Awesome post hotcobra. Was this the info elsewhere on SN,or did you type that all out from the Ford manual?

Either way,that's a LOT of crap to remove just to get to the heater core.I'm sure this'll be of big help to many.As for myself,if my HC ever starts leaking or plugs up for any reason,I'm just going to bypass it.I'll be damned if I'm gonna go through all that mess for that.I can live through the small couple of weeks it gets freezing here.

Again,nice job on the post.Should be added to tech articles if not allready there.

wish i could post all of it

MustangLX-5.0 said:

Awesome post hotcobra. Was this the info elsewhere on SN,or did you type that all out from the Ford manual?

Either way,that's a LOT of crap to remove just to get to the heater core.I'm sure this'll be of big help to many.As for myself,if my HC ever starts leaking or plugs up for any reason,I'm just going to bypass it.I'll be damned if I'm gonna go through all that mess for that.I can live through the small couple of weeks it gets freezing here.

Again,nice job on the post.Should be added to tech articles if not allready there.

Click to expand...

that was paste/copy from ford cd. i have just figured out pics for wire diagrams,but not ever using pc before ,yes im old as dirt..... and yes thats why i havent done mine and that was step 1 of 3