This thread will be relevant for anyone that needs to take apart their Gen 2 fx or qx70. Everything on the interior got ripped out and put back together so I know a thing or two.
First things first, Why I am doing a all of this work? The Vehicle I decided to go for had a lot of problems I was not initially aware of but I was willing to fix. I gave myself 2 weeks to tackle it and I am making good progress.
Problems;
- The wiring harness starting from the driver side fusebox and running the entirety of the vehicle to the passenger side had some chewed wires. Specifically in the rear of the vehicle where the harness connected to the amp there was chewed cables etc.
- The music sounded extremely quiet and terrible so needed to diagnose that.
- One of the windows would not work.
- The radio screen would intermittently cut out and reset.
- The backup camera returned a non existent fuzzy feed.
- A/C system sounded extremely loud.
- Wobble/noise in one wheel.
- Ebrake got burned by prev owner as I was following them to sign papers.
I think that’s everything, besides how dirty etc it was, Ill leave out most of the cleaning and extra info and leave this mostly for the process.
So what I needed to do was get the electrical situation sorted out, test and replace electronics, add whatever I wanted to add, put everything back together, get suspension problems fixed, work on any mechanical issues.
In hindsight the harness wasnt that bad and probably could have been repaired but with electrical stuff I didnt want to take a chance.
Due to the dirty condition of the vehicle I also wanted a chance to clean everything and get rid of any mold etc.
First trip was 2 hours home where the vehicle performed to the best of its abilities, It had a cel for the MAF sensor but the seller lmk that ahead of time so I came with a new one. The next trip was to the diy car wash where I spent 3 days removing trim and vacuuming / washing ALL of the cracks and crevices. I plastic bagged any connectors and fuse boxes etc and went to town cleaning.
After the cleaning came the checklist of what needed to be replaced. I concluded that at minimum I needed a new Amp, Airbag modules, wiring harness, carpet, speakers, weather seals, seats, and steering wheel.
I also decided to add multiple layers of sound proofing while I was in there.
Next trip was to the junkyard where I spent 2 days completely stripping a gen2 fx35. I grabbed the wire harness, modules, and weather seals on day 1. Day 2 I grabbed the infotainment, speakers, and trim as well as some extra trim pieces in case things were broken or too dirty.
Dismantling the Q;
The next day I proceeded to strip the Qx70. I started with the seats as it was the hardest thing to remove at the junkyard and would free up a bunch of room. Seats are easy just move the seat back and forth to expose the 2 bolts in the front and 2 in the back. Then disconnect harness and your good to go. The rear seats have pull tabs on the bottom and then the backrest requires dismantling the trunk roof speaker trim and the seat belts. Take photos of how things are situated. The seats line up but the seatbelts etc may get confusing. Also I believe the seats have a order, the bigger passenger side one has to come out before the single driver side back does.
Once the seats are out then its time for the center console trim.
This is pretty straight forward if you take your time to look for screws. Start at the back with the ac vent and work your way up. Make sure your ebrake is on when removing the shift knob. Also leave the metal gate at the rear of the center console and the yellow srs airbag module under it.
Once the center console is out you can head towards the pillar trims, headliner and trunk trim. The dashboard area I would save for last on a fresh day.
Removing Dash;
Not necessary for carpet replacement, wire harness replacement, or sound deadening.
To start with the dash I recommend going at the glovebox etc first since its the easiest to take out. After that start hitting the side panels of the dash where they meet the door. After that go for the trim that has your trunk release etc then steering wheel column. Itll be easy if you unscrew the locking bolt in the middle of the steering wheel but DO NOT unscrew it all the way it will save you a lot of time from putting it back together. Next go to the top where the ac vents pinched against the windshield are and remove the clips from in there. I believe the odometer also had to come out so slowly work out the trim surrounding it which should be easy after disassembling steering column.
Next look for any remaining connected wires. Specifically for the push to start and the tweeters on both corners of the dash. Lastly the steering wheel may need to come out. Grab a sharpie and mark the orientation its in on a visible but inconspicuous area, also mark the clockspring etc to make lining up easier. Grab tape and when you careful disconnect the steering wheel from the clock spring tape it in its exact orientation dont spin it. Next make a nice clean area to put the dash, its kinda heavy and the soft trim material is prone to scratches and punctures very easily.
Once thats all said and done you should be ready to pull out the dash!
Wiring;
Disconnect the battery safely!!
Do this WITH the replacement harness so as you disconnect you reconnect immediately!!
Obviously do not feed the harness through holes if you havent pulled the original harness out yet to avoid breakage
By your feet where the fusebox is you will see a thick harness of cables. Make sure you only unplug the connectors associated with the wiring harness. There is a cool clamp lock that you flip down and that releases the main harness. Unscrew the ground bolt and then slowly start pulling the harness up. Your going to see one cable leading to the center column towards the passenger side, thats for the kickplate light so just disconnect it or cut it if your brave and can quickly wire it back. You also have the off shoot for the drivers seat and srs yellow connector for the center console module.
Next your going to run into the seatbelt srs airbag cables. As long as your battery is disconnected your safe to remove. Slowly pull out the black internal connector and then you should be able to pull it loose. Then unplug the other 2 connectors.
Next where the back seats are you will see the harness lead in two directions, one towards the trunk and the other towards two circular cutouts by the seats. If you twist open those lids you will see regular connectors you can unclip. Take photos of all the mounting spots where the cables are clipped onto for organizing later. Its very important.
Once thats done you move to the trunk area walls. The harness splits here again. One way towards the headliner and the other towards the floor of the trunk. The headliner is a quick few connectors and another srs connector and maybe a ground bolt. Dont try to pull out the roof connectors its unecessary just disconnect when possible.
The trunk has your tail lights, different harnesses leading to underneath the vehicle, and harnesses going to the amp and srs module. Be very careful removing the tail lights. Everything comes out as one piece and is again pretty straight forward so just dont yank anything and make sure you got every single connector. The bumper needs to get removed for the sensor cable unless you have room underneath the vehicle to do so upside down as its easily accessed like that as well. Towards the middle of the trunk on the underside there are two connectors in a difficult to reach area that are also tied to a cable that has nothing to do with the harness. Cut the tie tying these two cables together and disconnect the connectors so you can pull them out. Same thing for the other two connectors located to the right corner underneath the vehicle.
Once your back inside proceed to disconnecting a few more connectors and head back to the cabin. This is the same as the other side and once you reach the glovebox area you have another one of those cool clamps to connect the main
harness.
Removing Floor;
With all of the previous work done this is going to be the easy part. Just slowly start pulling up all of the carpet. The carpet around the center console you may need to cut in a few spots but besides that it should all come out in one solid piece. The only confusing part is the rug behind the gas pedal. The gas pedal has a secret compartment in the front base that you pry up to reveal two bolts. Be careful unscrewing those bolts as one of mine sheered off.
Sound Proofing;
This is a question that gets asked a lot and honestly it depends on the person. Some people will say theres not a noticeable difference while others will say that its like night and day with the sound deadening. After doing some research sound deadening really only works if applied correctly and in layers. Yes you can go ahead and just do kilmat and be done with it but if your already in the car doing all of this work you might as well take advantage and do the job the right way. With that being said just using kilmat is not the full job, the other materials you can add is CCF or closed cell foam, MLV mass loaded vinyl and decoupler layers such as acoustic foam. The recommended order is the kilmat (butyl), CCF (acts as decoupler or dead space), and then MLV. There are better alternatives for butyl with better stats such as amazons very own in house ones but I used kilmat before so I went with them. After layering it through out the vehicle I put a layer of CCF down, then I realized that I may be doing a ton of work for something that I dont have running yet so I abandoned the rest of the deadening until a later date. Instead I opted to add a few mat cut outs and a water proof tarp as the final layer before the oem carpet.
Putting the floor in;
Before layering down the rest of the material, right after the kilmat I put down the foam inserts that are located in the deep pit areas in front of and behind the front seats. These foam foot inserts are needed as the carpet will just cave in so be careful removing them and make sure to put them back. Once I put all of that in I added the CCF and water proof tarp. The water proof tarp is for those pits I mentioned earlier, they do not have drain ports and thus hold water/moisture indefinitely. There was a swamp in mine, and in the fx I stripped there was a small puddle even though it had not rained in weeks and had been sitting in the lot for over a month. So to mitigate issues with future spills I decided to go ahead and just add the tarp so that it holds the moisture on the carpet layer for easy clean up.
Things I encountered;
the Harness even though different models still connected perfectly everywhere. I did not encounter a unknown connector.
The seat harnesses have a extra cable leading towards the center console. Its yellow and it plugs into the srs module underneath the rear of the center console where the a/c vents for the rear are and the metal arch which I left on.
These connectors did vary by model so swapping harnesses is not entirely possible safely so do this at your own risk. The reason for this is that separate from the dash, the inner workings of the dashboard has a bunch of harnesses interwoven with the frame. I would never attempt to remove this as it looks complicated. Those cables connect to the shift assembly and center console ports. They also connect to the srs module so you either leave your old srs module and connect just the one srs cable or you install the new one and connect the two from the harness. I went with option B, the more airbags the better lol.
Besides that I did not have any other issues with any connectors.
On to the speakers. So the issue I mentioned earlier about bad sound and quiet volume was due to...... none of the doors having speakers

So went ahead and started going door by door to replace the wiring harness and/or speakers. The two front doors are simple, you unscrew the window glass, slide out the window from the top. Then remove the bolts outlining the panel so you can pull it out. Be sure not to unbolt the actual window rails.
With that just follow along the wire harness for the door and as you remove connectors connect the new ones.
The rear doors is a little trickier as their is no removable panel. I did not swap the wiring harness on these instead I saw that the previous owner spliced in two cables into the harness so I went ahead and wired those to the new speakers.
With that I was done with the bulk of the work.
Now I had to clean up any on going issues. I currently had fixed the wiring harness situation, fixed the music situation, and fixed the window situation as well as the Radio screen. What was left was to test the A/C and Backup camera. As well as fix the new problems.
New problems;
My gauge cluster turns on but none of the gauges move. I did some digging online and some people said that accidentally swapping two of the connectors for the radio unit can cause issues. Dont test it out! I tried it and immediately something started burning but thankfully nothing seems to be damaged.
So need to diagnose my gauge cluster, the next issue is the eject button doesnt work on the radio, the A/C unit wont come on, and some sort of parasitic drain is going on as my battery keeps dying. Next I accidentally broke the clock spring for the steering wheel, and lastly I need to replace two seats.
My current order of work will be the clockspring/steering wheel. Then Ill move on to the Gauge cluster fix by possibly just swapping it for a new one. After that Ill check to see if everything works. Will update soon. Also let me know if I should include photos at the end as well?