buckwheat Posted May 9, 2015 Share Posted May 9, 2015 I know this has been covered multiple times, but I want to get opinions on a few different issues. My truck did not come with AC, but I have a parts 89 Cherokee with it. So I plan on getting the under dash box (heater box?), controls, and misc parts from it. I plan on reusing the compressor and condensor unless anyone can think of a reason why I shouldn't. How much of the dash do I have to remove to get to the heater box? I know the lower dash is a minimum, but what else do I have to take loose to get enough wiggle room to pull the heater box out? Can I reuse the evaporator and heater core, or should I replace them while I have the box out? Comparing cost vs. convenience. I know I should get a new drier and hoses. Are there premade hoses or do you make your own? How do I convert from R-12 to R134a? Should I look at getting parts from a 95+ Cherokee? Does anyone have photos or a write-up for the extra wiring under the hood? I know I will need something to the compressor, but what else do I need? Does anyone have ideas on putting extra fan(s) in? I've been thinking about deleting my mechanical fan and putting in two electric fans. Would this be a good idea? And are there any extra parts I need to add that I haven't mentioned? Are there any write-ups with photos? Or any good place for parts? Sorry for the long post/ lots of questions. Thanks for all the ideas! Link to comment Share on other sites More sharing options...
Marine1Texas Posted May 9, 2015 Share Posted May 9, 2015 HVAC box needs no dash removed. you should be able to get to in from the floor. converting to 134 is just the connection and seals. Make sure to clean up the old compressor good and put the 134a oil in before filling it will 134a. most parts should be able to reuse. just make sure once you get everything together to suck all the air and any moister out. You can keep heater core if it is still good. your need a new dryer. If you willing to spend the money, new heater core and evaporator is good because you will not have to go back in the box for many years to replace something with possible leak. I wish I could give you a write up. I did install my a/c for not a/c truck. I used the under dash a/c unit with heater. Link to comment Share on other sites More sharing options...
Eagle Posted May 9, 2015 Share Posted May 9, 2015 The heater core in my '88 Cherokee popped about four or five years ago. If yours is the original, it's on borrowed time. Much better to start new since you'll be in there anyway. Ditto for the evaporator. Link to comment Share on other sites More sharing options...
buckwheat Posted May 9, 2015 Author Share Posted May 9, 2015 Noriyori_Kudo - You say I do not have to take the dash apart to get the HVAC box out? That would be great. I know there are 6 bolts that go through the firewall that I have to remove to get it out. Anything else I need to take apart? Eagle - I was afraid I would want a new heater core and evaporator. Nothing like doing a job the right way the first time. Ouch on the $$$ side though. Anyone know what kind of nightmare I will be getting into with the wiring? Wiring is always what scares me the most. Link to comment Share on other sites More sharing options...
Marine1Texas Posted May 9, 2015 Share Posted May 9, 2015 Here are some pictures of the removal screws and box Hope those pic's help out a bit. If you want you can always remove the piece of plastic that runs at the bottom of dash. runs from one side to other with ash tray. I removed it, however found out later I did not have too Link to comment Share on other sites More sharing options...
dasbulliwagen Posted May 11, 2015 Share Posted May 11, 2015 Kudo... Have you ever pulled the HVAC box of of an mj or xj? I don't think you have. The dash does need to come out to change the box. I've done it. Please stop commenting on things you have no experience with. Link to comment Share on other sites More sharing options...
Alexia Posted May 11, 2015 Share Posted May 11, 2015 Kudo... Have you ever pulled the HVAC box of of an mj or xj? I don't think you have. The dash does need to come out to change the box. I've done it. Please stop commenting on things you have no experience with. Yep. The dash must be removed in all years of XJ and MJ models. The HVAC box splits into a top and bottom half. Link to comment Share on other sites More sharing options...
buckwheat Posted May 11, 2015 Author Share Posted May 11, 2015 So I will need to remove the ENTIRE dash? Or just take off the lower panel and loosen the top bolts on the upper dash? Link to comment Share on other sites More sharing options...
Minuit Posted May 11, 2015 Share Posted May 11, 2015 The entire thing. Link to comment Share on other sites More sharing options...
Alexia Posted May 11, 2015 Share Posted May 11, 2015 So I will need to remove the ENTIRE dash? Or just take off the lower panel and loosen the top bolts on the upper dash? The entire thing. You can take off the lower panel, loosen the two side lower bolts, and remove the screws along the top then sort of flip it down and out from the right a bit. It is still a pain and the center console has to be removed as well to make it easier. Excpect a minimum of eight hours to do this. Link to comment Share on other sites More sharing options...
gogmorgo Posted May 11, 2015 Share Posted May 11, 2015 This. I tried the "loosen side bolts and tilt it" method when I was patching up my dash harness after my headlight switch caught fire. I saw it in a heater core replacement thread. I don't know who came up with it, but I'm reasonably confident it's impossible. It wasn't enough space to get at the wires behind the dash, let alone pull the heater core or box. And eight hours for the first time r&r'ing the dash probably isn't too far off the mark, either. That's about what it wound up taking me. Finding a decent write-up (with pictures) will be a huge help. Link to comment Share on other sites More sharing options...
Marine1Texas Posted May 11, 2015 Share Posted May 11, 2015 you all don't know what you talking about dasbulliwagen ! No reasoning with a know it all You do not need to remove the whole dash. if your just getting to the HVAC box you can do it all from the floor. If you want to remove the plastic piece that go's from one side to the other that contains the ashtray you can, but not have too. The Box does not come out easy just does not fall out with taking screws out, need to do a little side way motion tug. If you want to remove the whole dash go do it, no skin off my back, however I have done this before and I post the picture below to show you my results. I have noticed time and again this comancheclub you have users who insult over and over. Put the pictures up to and show it This is a under dash unit. to put in, requires full removable of HVAC box. removing the box only, no ducting or heater core. Above pictures with screw and bolts removed. If one wants to pull the plastic strip that go's the length with ashtray that would be all needed. Why would one pull the top of dash, there are no bolds there it is just ducting for the vents. if you pulling and swapping the HVAC box out no need to pull your ducting. When your putting in the new control unit with a/c then you just pull the plastic bezel go's over the instrument cluster. It took my son and I 5 hours to complete everything. that included installing new wiring and all new a/c parts. I know when done 1st time it can take a bit, and if your unsure. look at all posts, look at the pictures, get your book, look at it, and then plan your attack on your job. Link to comment Share on other sites More sharing options...
64 Cheyenne Posted May 11, 2015 Share Posted May 11, 2015 Aint no way in hell Id hang that thing under my dash when I could do my homework and get AC that looks like it came from the factory... Link to comment Share on other sites More sharing options...
relyt120 Posted May 11, 2015 Share Posted May 11, 2015 :hmm: Taking the dash out is really no big deal, definitely a lot less work to go ahead and take the whole dash out than to try to work around it, if it is possible or not. Link to comment Share on other sites More sharing options...
Minuit Posted May 11, 2015 Share Posted May 11, 2015 :agree: If I ever needed to do this job on my Thunderbird or something with a really complicated dash, sure, I'd try to see if I could work around it, but there's really nothing to taking the whole thing out on an XJ/MJ. Hardest part is getting the defroster bezel on and off. And regardless, when you've taken it far enough apart to even be able to move it around a few more bolts will have it all the way out! Link to comment Share on other sites More sharing options...
sloride Posted May 12, 2015 Share Posted May 12, 2015 My experience has been you have to drop the dash. I would have loved not to do that. Defrost reveal molding pops off easily. Get a flex spring driver to get to the screws at the top of the dash especially the ones driver side are a bear to get to. I replaced the Phillips screws with square head screws got ease of assembly. Take center console out if you have one. Drop the "knee knocker" panel that goes side to side. Drop the steering column, two fasteners. Loosening side wall braces when you do that. Loosen two screws on lower each side of dash. Your dash will be loose at this point. Protect top of steering column from scratches because your dash will leave its mark if you're not careful. There's a right up with pics I have somewhere that someone did. If I can find it I'll post it. Link to comment Share on other sites More sharing options...
sloride Posted May 12, 2015 Share Posted May 12, 2015 http://www.cherokeeforum.com/f51/dash-removal-35444/ Link to comment Share on other sites More sharing options...
buckwheat Posted May 12, 2015 Author Share Posted May 12, 2015 Awesome. Thanks for the advice guys. And thanks for the write-up, looks super detailed. Hopefully I'll be able to jump in and do it sometime soon, before it gets too hot. Only thing that is holding me back right now is my MJ is my daily driver. If its an 8 hour job it will probably take me 16 or more. So I need a three day weekend before I start it. Link to comment Share on other sites More sharing options...
johnj92131 Posted May 12, 2015 Share Posted May 12, 2015 Buckwheat, Read up on all the procedures. Then go to a pick and pull yard with any Cherokee. Practice on that Cherokee. Make what ever mistakes you need to learn from on that Cherokee. Then find another Cherokee to do it all over again. By the second time you will have it down. Then start on your own truck. If you get stuck, go back to the Pick and Pull for more practice. Take lots of your own pictures, find the same year Cherokee as your Truck and use that one to pull the complete wire harnesses. Label all the ends you take off. Do this and you will have something that looks just exactly like what the factory installation is. I did a duplicate of a factory air installation on my 1969 Corvair back in 1970 or 71. A whole lot harder then than it is now. Link to comment Share on other sites More sharing options...
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