Introducing Big Juicy

[hear]

I also apparently have a NSS issue, getting code P1899 and am able to start in R & D. The thing is, I replaced the NSS & re-wired a new pigtail, so I didn't expect to to have a problem here. When I replaced the switch, there were two choices: NS240 & NS240T. No clue what the difference is, but I went with the T version since the picture showed it coming with a new o-ring gasket thing. I noticed that it wasn't identical to the one I took out, most notably the plunger was longer, which probably means it's engaged more than it should be? IDK how it actually works.

The wiring is obviously likely culprit, but I THOUGHT I made triple sure I was wiring like for like, I snipped & soldered one at a time to avoid any mixups.

= = = = = = = =

I also had a P0743 (torque converter lockup issue), but that was almost certainly due to the fact that the PO had run his own ground wire up into the cab somewhere and simply twisted that into the 1" of wire coming out of the plug, AND/OR the fact that that "splice had come apart" AND/OR the fact that neither that nor the signal wire had any insulation near the plug. I made a slightly better temporary fix on all that and headed out on my trip after clearing the codes.

On the way there, I still had the code and didn't notice it locking up, but at some point on the trip the code cleared on it's own and the TC started locking up. The wiring is still ugly down there and a replacement pigtail doesn't seem to be something anyone sells, so I need to figure out how to solve that soon.

 

[hear]

This ATF leak is going to be an enigma. Basically every time I parked it on pavement over the past 3 days, there would be a nice sized ATF spot under it. I drove it home from Disney (5 hrs), shifted fine, temp never got over 200 except at one particularly long stoplight. Parked it on the street overnight, no leaks, or at least nothing on the ground.

Yesterday morning I moved it into the garage and there were no drips all day as I checked on it. Then last night there's a huge puddle under it. The only reason I can figure it didn't drip on the street after the long drive was that the 65mph wind blew it all out and it took the better part of 24 hrs to fill up the skid plate enough to eventually make it drip on the garage floor.

 

[hear]

I guess I haven't updated this in a while, and I need a place to collect my thoughts so I can remind myself what I was thinking as I go. For those bothering to read all this, get ready for a long one. A lot of this has been covered in threads on the main forum, but if you're going to have a build thread you may as well maintain it.

ATF leak: seems to have been coming from the dipstick tube, which was removed when I dropped the trans. If I put it in at the depth I think it needs to be, the bracket on the dipstick tube doesn't line up with the hole in the bell housing. If I put it at the right depth to make those holes line up, it leaks like a sieve. So I put it in at "max depth" with a new O-ring and also some "right stuff" RTV and that seems to have solved it. The tube still has some play, so I feel like I need to fab up a piece to allow it to bolt into the bell housing like it always used to do. Baffled how it doesn't line up anymore, but I've had no luck trying to find anyone who knows anything about this. All I know is that it hasn't leaked since I took those steps.

TCC: I replaced the pigtail and I'm 90% sure it was still working after I did so. But when I took it for inspection this week I got that same P0743 code, and upon inspection I'm not seeing the slight RPM drop that I had been seeing so clearly it is not working.

NSS: the jeep will start in any gear, even with the NSS unplugged, so there must be a short somewhere upstream. I'm still getting the P1899 code that showed up back in August.

Reverse lights: they don't come on, at least in part because glove box fuse #7. Seems likely related to my NSS problem above. At one point with a new fuse I managed to get them to come on while the switch was unplugged. And then a gentle wiggle of the unplugged NSS pigtail popped the fuse. I did some minimal inspection today and it looks like the harness side connector has exposed wires coming into the plug (like the insulation has shrunk back), and if that was twisted just right... SPECULATION ALERT {I bet the violet/white wire touches the violet/black wire to make the lights come on w/o going through the switch. And if they are twisted in just a differently right way the violet/white wire probably touches the black/white wire which completes the actual neutral safety circuit. }. I have to drop the skid in order to really get at that wiring, and I just don't have the desire to do that just yet.

I will add that it is AWFULLY FISHY that I'm having 3 electrical problems that all join up in basically the same place on the harness. What I really need to do is to pull that entire portion of the harness out and go over it with a fine toothed comb and fix any issues. OEM connectors are ideal, but (a) so far it's been hard to find part numbers for them and (b) they're going to be more expensive than just replacing with some new waterproof connectors, so I'll probably go down that path.

CEL light: I'm a living joke, my CEL actually was burned out. Replaced that, which included driving to Autozone w/o a cluster, which was mildly jarring. For reference, the bulb is a "74" although I'm thinking I'm just going to replace with LED's since now the CEL is way brighter than any of the other lights. The bulb being burned out does explain why the initial P0743 code didn't make the CEL come on, which was always a bit of a mystery. I should've noticed it not flashing on when I started the jeep, but that's water under the bridge.

O2/Cat not ready: part of the inspection came back with the cat, o2, and o2 heater "not ready." Never had any o2 sensor codes before, but this MAY be related to the fact that I have not driven it at all over the past 5ish weeks, so I'm hoping that's it. Regardless, I have a pair of new NKT O2 sensors on hand should I decide to replace them. I'm hesitant to just throw parts at it given that they had never given me issues prior.

 

[hear]

Spent most of last night tracing wiring diagrams to figure out the wiring route of the NSS & TCC, only to find out that the FSM we have linked on the sticky thread is actually for the 2003. I've alerted the authorities, but so far it hasn't been fixed. I have the correct FSM now, and it makes way more sense compared to what I actually see under the jeep. It does make me wonder what other subtle differences there are between 1997 & 2003. Like all my dipstick problems...is that a 2003/1997 variance issue and I don't have the right o-ring or something? I'm questioning everything at this point.

For future readers: there isn't any great way to tell which year the FSM is for, but your best bet is to look in the first few pages for the VIN decoder. Make sure it shows how to decode '97 and not '03.

I need to find a window of time where I can be w/o the Jeep for the length of time it takes to clean up the under body wiring, because that's going to solve a lot of problems. I have new connectors arriving tomorrow, would love to get this done before Christmas.

In the meanwhile I did some preliminary testing on the upstream o2 sensor, and it seems to get +12V when it's supposed to, and grounds when it's supposed to. I'm not convinced it was actually plugged in completely; we had it unplugged back when we did the RMS, since we had to drop the exhaust (to either drop the transmission or the oil pan, I can't remember what caused what), so maybe it didn't get plugged in all the way. If it wasn't plugged in I would've expected it to run rough or something, but this thing has always run really well. So maybe it was plugged in, IDK.

I drove it for about an hour today, code reader still says not ready. I plan to drive as much as I can this week to see if I can get those sensors to "get ready." If not, I have new NKTs that I can put in, but that feels like throwing parts at it. Once again, I don't know if they've been saying not ready for a long time, or if this is a recent symptom. You think you're in tune with your vehicle until something acts up, and you realize how much you don't know about your vehicle.

 

[mrblaine]

Spent most of last night tracing wiring diagrams to figure out the wiring route of the NSS & TCC, only to find out that the FSM we have linked on the sticky thread is actually for the 2003. I've alerted the authorities, but so far it hasn't been fixed. I have the correct FSM now, and it makes way more sense compared to what I actually see under the jeep. It does make me wonder what other subtle differences there are between 1997 & 2003. Like all my dipstick problems...is that a 2003/1997 variance issue and I don't have the right o-ring or something? I'm questioning everything at this point.

For future readers: there isn't any great way to tell which year the FSM is for, but your best bet is to look in the first few pages for the VIN decoder. Make sure it shows how to decode '97 and not '03.

I need to find a window of time where I can be w/o the Jeep for the length of time it takes to clean up the under body wiring, because that's going to solve a lot of problems. I have new connectors arriving tomorrow, would love to get this done before Christmas.

In the meanwhile I did some preliminary testing on the upstream o2 sensor, and it seems to get +12V when it's supposed to, and grounds when it's supposed to. I'm not convinced it was actually plugged in completely; we had it unplugged back when we did the RMS, since we had to drop the exhaust (to either drop the transmission or the oil pan, I can't remember what caused what), so maybe it didn't get plugged in all the way. If it wasn't plugged in I would've expected it to run rough or something, but this thing has always run really well. So maybe it was plugged in, IDK.

I drove it for about an hour today, code reader still says not ready. I plan to drive as much as I can this week to see if I can get those sensors to "get ready." If not, I have new NKTs that I can put in, but that feels like throwing parts at it. Once again, I don't know if they've been saying not ready for a long time, or if this is a recent symptom. You think you're in tune with your vehicle until something acts up, and you realize how much you don't know about your vehicle.

I believe I have heard of an o-ring on the 32 dipstick tube but I don't recall ever seeing one. Everyone I have ever worked on and own uses what they call a grommet.

 

[hear]

I believe I have heard of an o-ring on the 32 dipstick tube but I don't recall ever seeing one. Everyone I have ever worked on and own uses what they call a grommet.


View attachment 297465

I bought a set of those that (probably exactly that) but it either didn't fit or I was too stupid to make it fit. Also worth noting, that grommet was not there when I removed the dipstick. Do you have a specific part number or link for what you have used? I'm not leaking but I know it's not set "right" as-is. I'm probably just one big bump away from a hot tranny mess.

 

[mrblaine]

I bought a set of those that (probably exactly that) but it either didn't fit or I was too stupid to make it fit. Also worth noting, that grommet was not there when I removed the dipstick. Do you have a specific part number or link for what you have used? I'm not leaking but I know it's not set "right" as-is. I'm probably just one big bump away from a hot tranny mess.

If you bought the set and can't use them, I'm glad to buy them from you since we use them pretty often. As for the o-ring, I can dig around and see what I can figure out.

 

[hear]

Update on all those electrical issues, so I can have my thoughts collected in one place.

I completely disconnected the underbody harness & pulled it up through the engine bay for inspection. In short, found several connectors with bare wires, which I already knew about. But after pulling back (read: breaking off) the old split loom, I found a number of cases of wires within the harness having their insulation missing in places, actually burned/ripped apart, one was simply cut... and then near one of the "forks" in the harness where it splits to the tail lights, o2 sensor, speedo, etc, the wires were stuck together as if they had very early signs of melting together. Maybe it was just pressure + heat + time, hard to say. This was the same area where most of the insulation problems were, so seems like this is all related.


On the left are 3 the wires that go to the neutral safety switch. The green/white & blue/green wires go to the tail lights, so that probably explains the blowing fuses. Under that is a brown/yellow & tan/white twisted pair that goes to the O2 sensor. Those also had their insulation missing and likely explains the issues with the downstream 02 sensor not being ready. The moral of this story is make sure your CEL bulb isn't burned out.

This is the section of wire from the neutral safety switch after the pigtail that connects to the NSS itself. It was in a "kevlar?" type insulation tube that showed some signs of being very high heat. The wires inside it did not fare well. You can also see the wires were bare at the connector itself, and twisted around each other. I suspect this had the effect of "jumping" the switch so the transmission always looked as if it were in P or N to the NSS circuit.

Next up we have the torque converter lockup wiring. First, you can see that the wires were just burned/ripped/destroyed/loved by physical processes. How I *ever* got this working over the summer is pure black magic fuckery. The orange/light green wire goes up to the middle plug on the PCM, but apparently was cut by a prior owner, and then replaced with a new black wire that exists external to the harness. I knew that wire was there, but hadn't ever traced it fully. When I replaced the connector a few months back I mistakenly swapped the wires, so all the mess in the world didn't amount to a hill of beans because I screwed up the job.

I opted to leave the PO fix alone because the harness looks clean in this spot and I didn't want to open it up further at this time, it's held strong this long, and the new wire he ran is heavier gauge with much better insulation so I can live with it not being in the loom. So there is an orange/green wire still poking out at the PCM and then also taped off near the TCC plug in the loom.

I pulled back the loom on each section but didn't find anything other than what's pictured. If there are issues further upstream it will be a real pain to see much less fix. With everything hanging over the grille support bar, I'm able to see the wires about to the block. So about 8'-10" of clean wiring, and then I haven't put in the effort to see any further. On one hand, I should expect issues everywhere since this was such a mess, but on the other hand the mess was confined to one specific area so I don't expect any other issues.

Next up: fixing it all.

 

[hear]

If you bought the set and can't use them, I'm glad to buy them from you since we use them pretty often. As for the o-ring, I can dig around and see what I can figure out.

The ones I bought were like $5, I can just send them to you. I was just hoping to verify that I got the right grommets compared to what you typically use. I found the O ring part # and got a replacement that was pretty much identical (except much better condition) than the old one.

Also worth noting that the actual 1997 FSM (not the 2003 we have linked in the sticky thread) mentions the o-ring. A grommet (or an actual seal) seems like a much better design to me.

 

[mrblaine]

The ones I bought were like $5, I can just send them to you. I was just hoping to verify that I got the right grommets compared to what you typically use. I found the O ring part # and got a replacement that was pretty much identical (except much better condition) than the old one.

Also worth noting that the actual 1997 FSM (not the 2003 we have linked in the sticky thread) mentions the o-ring. A grommet (or an actual seal) seems like a much better design to me.

View attachment 300871

My 97 uses the grommet as a point of reference.

 

[NashvilleTJ]

Update on all those electrical issues, so I can have my thoughts collected in one place.

I completely disconnected the underbody harness & pulled it up through the engine bay for inspection. In short, found several connectors with bare wires, which I already knew about. But after pulling back (read: breaking off) the old split loom, I found a number of cases of wires within the harness having their insulation missing in places, actually burned/ripped apart, one was simply cut... and then near one of the "forks" in the harness where it splits to the tail lights, o2 sensor, speedo, etc, the wires were stuck together as if they had very early signs of melting together. Maybe it was just pressure + heat + time, hard to say. This was the same area where most of the insulation problems were, so seems like this is all related.


On the left are 3 the wires that go to the neutral safety switch. The green/white & blue/green wires go to the tail lights, so that probably explains the blowing fuses. Under that is a brown/yellow & tan/white twisted pair that goes to the O2 sensor. Those also had their insulation missing and likely explains the issues with the downstream 02 sensor not being ready. The moral of this story is make sure your CEL bulb isn't burned out.

View attachment 300859

This is the section of wire from the neutral safety switch after the pigtail that connects to the NSS itself. It was in a "kevlar?" type insulation tube that showed some signs of being very high heat. The wires inside it did not fare well. You can also see the wires were bare at the connector itself, and twisted around each other. I suspect this had the effect of "jumping" the switch so the transmission always looked as if it were in P or N to the NSS circuit.

View attachment 300858

View attachment 300860


Next up we have the torque converter lockup wiring. First, you can see that the wires were just burned/ripped/destroyed/loved by physical processes. How I *ever* got this working over the summer is pure black magic fuckery. The orange/light green wire goes up to the middle plug on the PCM, but apparently was cut by a prior owner, and then replaced with a new black wire that exists external to the harness. I knew that wire was there, but hadn't ever traced it fully. When I replaced the connector a few months back I mistakenly swapped the wires, so all the mess in the world didn't amount to a hill of beans because I screwed up the job.

View attachment 300869

I opted to leave the PO fix alone because the harness looks clean in this spot and I didn't want to open it up further at this time, it's held strong this long, and the new wire he ran is heavier gauge with much better insulation so I can live with it not being in the loom. So there is an orange/green wire still poking out at the PCM and then also taped off near the TCC plug in the loom.

View attachment 300865


I pulled back the loom on each section but didn't find anything other than what's pictured. If there are issues further upstream it will be a real pain to see much less fix. With everything hanging over the grille support bar, I'm able to see the wires about to the block. So about 8'-10" of clean wiring, and then I haven't put in the effort to see any further. On one hand, I should expect issues everywhere since this was such a mess, but on the other hand the mess was confined to one specific area so I don't expect any other issues.

Next up: fixing it all.

Whoa - that’s nasty.

 

[hear]

My 97 uses the grommet as a point of reference.

Well I guess we can add this to the 97 quirks thread.

 

[PFPJeep]

Those torque converter clutch solenoid wires are toasted!

I'm sure you have combed the 97 FSM but here a quick cheat sheet I made of the wiring in that area.

 

[PFPJeep]

In case you're going to hack up that 99 harness. Here's the 99 Quick cheat sheet of the same connectors. The only change is the color of 1 wire in the Downstream Ox sensor.

 

[hear]

thanks for those @PFPJeep, and yes I do have a copy of the correct 97 FSM. Although I have to say that I hate the wiring diagrams in the FSM. I don't know if they changed how they were done over the years because it became impractical or what, but when I did the wiring on my CJ I had basically ONE big diagram with ALL the wires on it. It was great, I laid it out on the bench and could easily trace any circuit. The FSM is more laid out by functional circuit, so if you need to look at all the wires in the bundle you need to know where they're coming from/going to before you can have any prayer of finding them in the diagrams. As I was going through this, I thought about actually laying out the wiring more topologically in CAD. I may still do that, at least for the underbody portion of the harness.

As far as hacking on that harness, I took stock of the situation and realized that the fix really only involved about 8 or 10 splices, which I already have done, film at 11. That 99 harness is still untouched, I guess I'll sell it. I bet it's worth a fair amount.

 

[hear]

It's always darkest before the dawn. Was supposed to go wheeling on Saturday, and here it is late on Friday and I've not actually attempted to START the jeep since my wiring repairs. I was satisfied that it turned over, and since it was cold and the garage door was down I didn't actually fire it up until about 11pm Friday night. Crank, no start. And before long, I triggered the smoke release behind the dash. Needless to say I didn't take Big Juicy wheeling. (I did still go with my buddies as a plus-one, and had a great time just riding and spotting on a cold & rainy day. Worked out for the best.

Lots of other weirdness: no OBDII communication (would power up, just no sync), no voltmeter, no fuel gauge, other dash lights worked, fuel pump relay not clicking on with the key...probably other things too.

Short version of the troubleshooting steps:

• Smoke from behind the dash with the key ON, key off was ok.
• removed the steering wheel & dash to get a better look at the meltiness
• Red/light green wire melting visible through the speaker opening, in that mess of wires that ties into the umbilical from the firewall among other things.
• Same red/light green wire has burned through the insulation AND the electrical tape on the bundle that runs behind the dash over to the passenger side
• removed the tape on a large section behind the dash to look for other damage, found no additional trouble spots
• Still need to check the engine side from the firewall pass-thru to the PSM & S102 splice.

Took some digging because I had no idea what this wire went to and also I really thought it was red/dark green, but maybe that was the effect of the charring. Plus it was a small gauge wire...20ga which is a little odd but whatevs. Eventually I found it on the diagrams, and among other things, it controls the fuel pump relay (which wasn't clicking on with the key), the ASD, the PCM, and wait for it: the mother flipping TCC.

No small coincidence I rewired that and now the circuit that lives on is pooping the bed. Turns out the TCC uses a red/light green wire for ignition power and an orange/light green wire for communication from the PCM to the solenoid. I have not verified it yet, but I guess I mixed those up, partly because I suck and partly because who designs a 2 wire circuit with nearly identical wires that if you mix them up causes a fire?

I'll investigate that tomorrow ASAP. It occurs to me that the TCC plug actually fits both ways so just turning it over should technically solve the problem, although that would make the clip really hard to seat, so I'll probably just test with it flipped and then actually re-wire it, assuming my theory is right. This actually makes a ton of sense, and makes me feel a whole lot better about the rest of my wiring job. If I'm wrong about my theory, I'll probably leave a note for my family and put a .45 in my mouth. j/k

Last thought: as I'm unplugging everything in sight and removing the dash, I'm thinking "this is many people's first step in turning a working car into a stalled project that sits untouched in a garage for 20 years." You know, like my stupid CJ7 project.

 

[hear]

I'm also wondering why this circuit, which is protected by a 10A fuse in the #11 spot is allowing enough current to flow through it to melt the insulation on a 20ga wire without popping the fuse. I mean, if the wire melts before the fuse blows then the wire is the fuse. According to some chart I found, a 20AWG wire can handle 11A. I don't fully know what "handle" means but I would expect 11A to not melt the insulation.

Maybe I'll put a 2.5A fuse in and see if it pops. And then I guess I could remove the fuse and bridge the fuse slot with my ammeter to see how much current is actually flowing. Maybe it's only pushing 9A and there are less than ISO-spec on the number of strands in the wire or something that decreases it's actual capacity.

 

[mrblaine]

I'm also wondering why this circuit, which is protected by a 10A fuse in the #11 spot is allowing enough current to flow through it to melt the insulation on a 20ga wire without popping the fuse. I mean, if the wire melts before the fuse blows then the wire is the fuse. According to some chart I found, a 20AWG wire can handle 11A. I don't fully know what "handle" means but I would expect 11A to not melt the insulation.

Maybe I'll put a 2.5A fuse in and see if it pops. And then I guess I could remove the fuse and bridge the fuse slot with my ammeter to see how much current is actually flowing. Maybe it's only pushing 9A and there are less than ISO-spec on the number of strands in the wire or something that decreases it's actual capacity.

There was a batch of fuses from Harbor Freight that would not blow. They melted lots of wires. Try a known good 10A from a good supplier and see if that fixes the problem.

 

[starkey480]

My 97 uses the grommet as a point of reference.

The dipstick you sent me has an O ring not a grommet. If I remember correctly, you sent me the dipstick out of your 97 and I ordered a replacement for you that utilized a grommet.

The O ring leaked on mine and I ended up just searching around and found a generic O ring that fit.

 

[mrblaine]

The dipstick you sent me has an O ring not a grommet. If I remember correctly, you sent me the dipstick out of your 97 and I ordered a replacement for you that utilized a grommet.

The O ring leaked on mine and I ended up just searching around and found a generic O ring that fit.

All very possible.