The people here at JeepForum have been very helpful to me, so I thought I'd do this writeup as a way of saying thank you.
A couple things about the job. First off, I'm the type who prefers a job with 100 easy steps as opposed to 1 really hard one- so for many this writeup may seem too lengthy. Second, you should know in advance that after getting them (the heated elements) working again, I was pretty (or even very) disappointed with them. My 03 Avalanche's seats used to get so hot, you had to turn them down because it began to burn- they were awesome! this was what I was looking forward to with the ZJ. Perhaps its just my vehicle, and this wont be the case with yours, but the warmest the seats get is just BARELY above body temperature on HI. They do work though- you will hear the little clicking under the seat kicking the elements on and off, and you will feel the chill from the seat disappear faster than it would without it... But if you're expecting a heating pad effect, don't be surprised if this doesn't happen. I think they're supposed to be much warmer, and my guess is the modules under the seats may be to blame, because it seems like it turns the elements off too soon and lets the seat cool off too much between cycles. On the other hand, it may be the thermostat in the seat cover that's to blame... Anyway, on to the Writeup.
Obviously, this writeup is meant as a reference only, and implies no warranty, or guarantee. Should you chose to follow the steps contained herein, you do so at your own risk, and agree to assume full responsibility for any outcome. Note, this writeup involves using a propane torch to apply heat/flame to surfaces, which if over heated, may cause the vehicle to catch fire. In addition, you will be required to apply flame to a bolt that is less than 12 inches from fuel lines. If you are not fully confident that you can safely manipulate a torch with fuel lines less than 12 inches away, do NOT attempt this. Also, when using a torch there is the possibility of severe personal injury, so if you're not too terribly mechanically inclined or at least possess a basic familiarity with torch use, I'd recommend having someone else do this for you, or at the very least, have an experienced individual with you when you do this. Fuel leaks are especially dangerous, if your vehicle ever smells of gas don't attempt this until it's fixed.
Wire Brush (one small one large)
T-45 Torque Bit
Propane Torch (highly- repeat HIGHLY recommended, unless you really like bad days)
Needle Nose Pliers
Spool of Wire (18-14ga)
Liquid Wrench/WD-40 or whatever
Glue that remains flexible when cured. Silicon for example.
Plastic welding kit with rubberized plastic welding rods (used for bumper repair). I used harbor freights Item# 67102.
1) The seat is secured with 4 bolts, two in the front and two in the back. The front two are much more dangerous to remove, because they do not go through to the underside of the floorboard, they are mounted horizontally... meaning if you break one trying to remove it, you will not have a stud hanging out under the truck to work with, to get it out. So, DONT break any of the front bolts- take it as slow and easy as you have to, even if it means spreading their removal out over a couple days using penetrating oil. The good news is, the front bolts aren't exposed to the elements so their removal should not pose too much of a problem... But mine were still tough to remove because of the 15 year old thread lock. Okay now here's the skinny on the two rear bolts- they do go through the floor board and are exposed to the elements. Step one is to climb under and use your big wire brush to clean away as much dirt, grime and rust from the threads as you can. Don't lubricate the threads- we're going to be applying a flame to them and you don't need the oil catching fire.
2) Slide the seat all the way back.
3) Remove the front two bolts gingerly.
4) Slide the seat all the way forward and rock the seat back forward too.
5) Remove the plastic seat bolt covers concealing the rear two seat bolts.
***Don't do what I did. I am pretty well experienced, and on top of that, knew in advance that these bolts have a tendency to break, and STILL, as careful as I was being, managed to snap one off. They're NOT kidding when they say these things snap- so don't don't don't skip the next step***
6) Heat one bolt at a time. Grab your fire extinguisher or get your garden hose ready, whichever you prefer. Using torch, apply heat to the nut of one of the two rear bolts, from underneath the vehicle. I found that the under coating is very heat resistant, it didn't seem to want to catch at all, which was nice. It only took somewhere around 30 seconds of moving flame to allow the bolt to come out VERY easily... yes, it makes that much difference- you'll know its ready when the bolt just turns easily, like a normal bolt should. The heat makes a monumental difference trust me. If you're still fighting it, apply more heat- but be careful, obviously all this heat is heating up/burning the sub-carpet lining in the interior, creating the potential for fire. REMEMBER- the inboard bolt is less than 6 inches from fuel lines running along the frame rail, keep the flame angled away from them... and don't lay directly under them in case they do rupture/catch fire.
If you decided to skip this step anyway.. and manage to snap a bolt- not to worry. Just go back and follow step 6 for the broken bolt and use a set of vice grips on the remaining shaft of the bolt from underneath, and once its heated, turn it all the way through, with it exiting the nut from underneath the vehicle.
7) After you've heated the bolt, obviously turn off the torch and go up top and remove the bolt.
8) Repeat process for other bolt.
9) Recline the seat back, all the way back (important). Being careful not to burn your self on the hot seat feet, rock the seat up enough to expose the main connector. Slide the red locking tab out til it stops, and disconnect the connector.
10) Disconnect the seat belt connector.
11) Remove the seat and take it to the bench with the controls facing you.
12) Remove 3 screws holding panel on. 2 long ones are in front and a short third screw is on the back.
13) Disconnect black connector.
14) Unscrew both screws holding in lumbar switch. Note, I took one screw all the way out, and left the other dangling in the switch, and never had a problem with it getting lost.
15) Set panel to the side.
16) Disconnect 2 connectors on recliner motor.
17) Loosen 2 bolts holding recliner assembly on.
18) Rotate seat so opposite side now facing you and pull down, side, rear of seat cover, to reveal T-45 torque bolt
19) Loosen torque bolt, but don't remove.
20) Move seat to the floor upside down.
21) Unwind wire loops, holding lower seat cover to seat frame. Be careful. There is serious knuckle cracking potential here, wear gloves. And also note, that although I'm using side cutters here, I'm NOT cutting the wire loops... I'm just using their sharp point to get the unwinding started.