Changing the evaporator core in a 1997 Jeep Grand Cherokee limited is not too difficult IF you take your time and don’t get frustrated. This was on a 5.2 liter engine.
Several fasteners are hidden or nearly so and some of the electrical connectors have locking mechanisms to keep them from vibrating loose.
I was lucky and could work at this in my spare time because I have an extra vehicle. It took me 3 evenings after work to get every thing apart, remove the heater /AC box and get it apart and cleaned up. I also went ahead and replaced the heater core, as this is a one-time project I hope.
Once I got the parts correct parts I was able to get the heater box in and plumbing done in one evening.
I waited until I could get my buddy to bring his nitrogen tank and vacuum pump over so we could pressurize the system to check for leaks then pull a vacuum on it before putting the dash in. No need to go to all the trouble of installing the dash only to find a connection somewhere is leaking.
The dash was set in place the next evening and then buttoned up with all the connectors and dash trim. Then the key was turned and she came back to life!! Who Hoo!!
So here are the steps I took to remove everything.
On the inside of the Jeep
Ø Put both seats as far back as you can and tilted back as well.
Under the hood:
Ø Disconnect the battery and secure the lead from accidentally re-connecting as you are climbing around in the engine compartment.
Ø Assuming that there was a leak in the core (other wise why would you be doing this?) the AC system should be empty of Freon.
Ø Drain the coolant
Ø Remove the coolant overflow tank.
Ø Remove the PCM, Its mounted with 3 - 8 mm screws. 2 of mine came out but the 3rd broke off so I had to swing mine up out of the way. It turned out to be a PITA but I made it work.
Ø Next loosen the clamp bolt holding the dryer in place.
Ø NOTE: Even though the system has been discharged please wear your safety glasses and use caution when opening the lines!!
Ø Remove both AC lines. Plug the lines and openings to keep oil from dripping all over you and your driveway. You will need a couple sizes of special disconnect tools. I bought a whole selection of them from Advance Auto for about 15 bucks. Don’t try it with out the tools you’ll get frustrated and bust something.
Ø NOTE: The pipes for the heater core crush super easy!! It may be best to remove the hoses at the engine and pull the heater box out and the hoses along with if you’re not planning on replacing the heater core. I didn’t heed this and crushed mine trying to break the hoses loose.
Ø Slide the squeeze type clamps back away from the firewall and off the hoses or you wont be able to get the box out.
Ø There are 5 - 7/16 nuts to remove that hold the heater box against the firewall. One behind the PCM another the is hidden because there is a bundle of wires tied to it, 2 near the heater hoses and one behind the distributor cap. This one you may want to remove the Intake snorkel to get the nut off.
Ø Block the wheels so the jeep won’t move as we need to take it out of gear.
Now lets get back on the inside of the Jeep!!
v Turn on the ignition and put the shifter in low to get it out of the way.
v Remove the A- pillar trim on both sides, speaker trim that fits against the windshield, watch for the light sensor! Twist to remove it. Next the center dash trim and burled wood look trim if so equipped.
v Remove right (passenger) kick panel.
v On passenger side remove all those pesky electrical plugs connected to the fuse block. They all simply plug in and are keyed to keep them from going in the wrong place.
v There is a bolt above the fuse box and connector 13 mm if I recall that has to be removed to loosen the dash.
v Pull back the carpet near the center of the dash. There is a ½ inch hose here to take loose.
v Pull out the antennae connector and disconnect it if you can get to it at this time. There are also a couple of miscellaneous connectors under this side of the dash as well. Take your time and look around. I also removed the glove box to be able to get a better look around in there. Just a couple of screws are all that holds it in place.
v On the drivers side remove the plastic trim from under the steering column.
v Remove the knee block from under the dash and the metal brace beneath that.
v Remove the lower corner trim from the dash 2 screws and a clip.
v Behind the corner trim is a hole with a bolt way back in it. Remove the 13 mm bolt you find inside and move to the center console.
v Center console- pull back carpet from bottom of dash area . There is a metal plate with 2 bolts (13mm) to the floor and 2 to the bottom center of the dash.
v Remove the ashtray and behind it the screw into the dash.
v Disconnect the brake light switch. Tilt the steering wheel up and remove the tilt lever. Remove the 2 screws holding the plastic housing around the column. Once you have those out of the way disconnect the wiring harness connectors from the multi function switch and anything else in there. The multi function switch has a bolt thru the center of it to hold it in place.
v Remove the bolts from underneath the column that hold it to the dash.
v Be careful not to turn the wheel with it disconnected as I’ve heard that internal damage to the steering mechanism can occur.
v Remove the nuts along the top of the dash under where the speaker/defrost grill was removed.
v I also removed all the screws from the dash pad and took it out as well. I found out later that this was an un necessary step but not a complete waste as I thought it made handling the dash by myself easier. There were more places to grab a hold of it and to maneuver it for easier removal.
v You may want to cover the shifter console with a thick blanket
as the dash will be resting on it as you take it out.
v SLOWLY start to move the dash back and watch for missed connectors as you go. Once you have the dash loose remove it and place it somewhere out of the way.
v Here may be a good time for an adult beverage if you are so inclined.
v Now you can see the heater/AC box. You can finally see your prey!!
v There is one or maybe two 10 mm bolts left holding it in place along with a connector to the heater fan. The connector wires are red and black I think.
v There is also the AC drain outlet, which goes thru the firewall. It probably is stuck in place with RTV.
v Now if you haven’t missed any thing the heater box should come free with some gentle persuasion.
Once you have it out and on the garage floor or bench turn it upside down and start removing the screws holding the halves of the box together. One screw is under some of the ducting. Remove the ducting by pressing in on the snap connections. Once the box comes apart the evaporator slides out. The heater core is held in place with a screw on top of the housing as I remember.
Now if you haven’t gotten frustrated and taken a blow torch to your vehicle you should be ready to put it all back together again.
Remember take your time and if you start feeling rushed or stressed -walk away!!
I hope this guide has been helpful to you.
Visit me @ http://www.frankscammell.com
Several fasteners are hidden or nearly so and some of the electrical connectors have locking mechanisms to keep them from vibrating loose.
I was lucky and could work at this in my spare time because I have an extra vehicle. It took me 3 evenings after work to get every thing apart, remove the heater /AC box and get it apart and cleaned up. I also went ahead and replaced the heater core, as this is a one-time project I hope.
Once I got the parts correct parts I was able to get the heater box in and plumbing done in one evening.
I waited until I could get my buddy to bring his nitrogen tank and vacuum pump over so we could pressurize the system to check for leaks then pull a vacuum on it before putting the dash in. No need to go to all the trouble of installing the dash only to find a connection somewhere is leaking.
The dash was set in place the next evening and then buttoned up with all the connectors and dash trim. Then the key was turned and she came back to life!! Who Hoo!!
So here are the steps I took to remove everything.
On the inside of the Jeep
Ø Put both seats as far back as you can and tilted back as well.
Under the hood:
Ø Disconnect the battery and secure the lead from accidentally re-connecting as you are climbing around in the engine compartment.
Ø Assuming that there was a leak in the core (other wise why would you be doing this?) the AC system should be empty of Freon.
Ø Drain the coolant
Ø Remove the coolant overflow tank.
Ø Remove the PCM, Its mounted with 3 - 8 mm screws. 2 of mine came out but the 3rd broke off so I had to swing mine up out of the way. It turned out to be a PITA but I made it work.
Ø Next loosen the clamp bolt holding the dryer in place.
Ø NOTE: Even though the system has been discharged please wear your safety glasses and use caution when opening the lines!!
Ø Remove both AC lines. Plug the lines and openings to keep oil from dripping all over you and your driveway. You will need a couple sizes of special disconnect tools. I bought a whole selection of them from Advance Auto for about 15 bucks. Don’t try it with out the tools you’ll get frustrated and bust something.
Ø NOTE: The pipes for the heater core crush super easy!! It may be best to remove the hoses at the engine and pull the heater box out and the hoses along with if you’re not planning on replacing the heater core. I didn’t heed this and crushed mine trying to break the hoses loose.
Ø Slide the squeeze type clamps back away from the firewall and off the hoses or you wont be able to get the box out.
Ø There are 5 - 7/16 nuts to remove that hold the heater box against the firewall. One behind the PCM another the is hidden because there is a bundle of wires tied to it, 2 near the heater hoses and one behind the distributor cap. This one you may want to remove the Intake snorkel to get the nut off.
Ø Block the wheels so the jeep won’t move as we need to take it out of gear.
Now lets get back on the inside of the Jeep!!
v Turn on the ignition and put the shifter in low to get it out of the way.
v Remove the A- pillar trim on both sides, speaker trim that fits against the windshield, watch for the light sensor! Twist to remove it. Next the center dash trim and burled wood look trim if so equipped.
v Remove right (passenger) kick panel.
v On passenger side remove all those pesky electrical plugs connected to the fuse block. They all simply plug in and are keyed to keep them from going in the wrong place.
v There is a bolt above the fuse box and connector 13 mm if I recall that has to be removed to loosen the dash.
v Pull back the carpet near the center of the dash. There is a ½ inch hose here to take loose.
v Pull out the antennae connector and disconnect it if you can get to it at this time. There are also a couple of miscellaneous connectors under this side of the dash as well. Take your time and look around. I also removed the glove box to be able to get a better look around in there. Just a couple of screws are all that holds it in place.
v On the drivers side remove the plastic trim from under the steering column.
v Remove the knee block from under the dash and the metal brace beneath that.
v Remove the lower corner trim from the dash 2 screws and a clip.
v Behind the corner trim is a hole with a bolt way back in it. Remove the 13 mm bolt you find inside and move to the center console.
v Center console- pull back carpet from bottom of dash area . There is a metal plate with 2 bolts (13mm) to the floor and 2 to the bottom center of the dash.
v Remove the ashtray and behind it the screw into the dash.
v Disconnect the brake light switch. Tilt the steering wheel up and remove the tilt lever. Remove the 2 screws holding the plastic housing around the column. Once you have those out of the way disconnect the wiring harness connectors from the multi function switch and anything else in there. The multi function switch has a bolt thru the center of it to hold it in place.
v Remove the bolts from underneath the column that hold it to the dash.
v Be careful not to turn the wheel with it disconnected as I’ve heard that internal damage to the steering mechanism can occur.
v Remove the nuts along the top of the dash under where the speaker/defrost grill was removed.
v I also removed all the screws from the dash pad and took it out as well. I found out later that this was an un necessary step but not a complete waste as I thought it made handling the dash by myself easier. There were more places to grab a hold of it and to maneuver it for easier removal.
v You may want to cover the shifter console with a thick blanket
as the dash will be resting on it as you take it out.
v SLOWLY start to move the dash back and watch for missed connectors as you go. Once you have the dash loose remove it and place it somewhere out of the way.
v Here may be a good time for an adult beverage if you are so inclined.
v Now you can see the heater/AC box. You can finally see your prey!!
v There is one or maybe two 10 mm bolts left holding it in place along with a connector to the heater fan. The connector wires are red and black I think.
v There is also the AC drain outlet, which goes thru the firewall. It probably is stuck in place with RTV.
v Now if you haven’t missed any thing the heater box should come free with some gentle persuasion.
Once you have it out and on the garage floor or bench turn it upside down and start removing the screws holding the halves of the box together. One screw is under some of the ducting. Remove the ducting by pressing in on the snap connections. Once the box comes apart the evaporator slides out. The heater core is held in place with a screw on top of the housing as I remember.
Now if you haven’t gotten frustrated and taken a blow torch to your vehicle you should be ready to put it all back together again.
Remember take your time and if you start feeling rushed or stressed -walk away!!
I hope this guide has been helpful to you.
Visit me @ http://www.frankscammell.com
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