97-06 4.0 automatic wiring harness differences?

lee bland

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Hey, I bought a 2002 tj 4.0 with 32rh automatic, the po replaced the transmission(I don't know if he used thr right year model, or if the year matters) but he said after that he couldnt get it to run and said it was not getting power to the fuel pump! He cut and hacked up the factory wiring harness and then replaced it (with unknown year model harness) still wouldn't run until he did some jumpering on the bulb and white wire and the green and white wire at the fuse box under the hood! And straight wired the fan to a toggle switch because it wasnt working! Ok now , lol, it will run at high idle(around 1200 to 1500rpm) and if I drive it, it won't shift out of first gear! And no guages! I'm thinking he used the wrong harness because at connector 103, (black plug on firewall), the wire colors don't match from the engine side to the firewall side of that connector! Any advice would be greatly apriciated, thank you!
 
Hey, I bought a 2002 tj 4.0 with 32rh automatic, the po replaced the transmission(I don't know if he used thr right year model, or if the year matters) but he said after that he couldnt get it to run and said it was not getting power to the fuel pump! He cut and hacked up the factory wiring harness and then replaced it (with unknown year model harness) still wouldn't run until he did some jumpering on the bulb and white wire and the green and white wire at the fuse box under the hood! And straight wired the fan to a toggle switch because it wasnt working! Ok now , lol, it will run at high idle(around 1200 to 1500rpm) and if I drive it, it won't shift out of first gear! And no guages! I'm thinking he used the wrong harness because at connector 103, (black plug on firewall), the wire colors don't match from the engine side to the firewall side of that connector! Any advice would be greatly apriciated, thank you!

Could I just re-pin the wires on connector 103?
 
Hey, I bought a 2002 tj 4.0 with 32rh automatic, the po replaced the transmission(I don't know if he used thr right year model, or if the year matters) but he said after that he couldnt get it to run and said it was not getting power to the fuel pump! He cut and hacked up the factory wiring harness and then replaced it (with unknown year model harness) still wouldn't run until he did some jumpering on the bulb and white wire and the green and white wire at the fuse box under the hood! And straight wired the fan to a toggle switch because it wasnt working! Ok now , lol, it will run at high idle(around 1200 to 1500rpm) and if I drive it, it won't shift out of first gear! And no guages! I'm thinking he used the wrong harness because at connector 103, (black plug on firewall), the wire colors don't match from the engine side to the firewall side of that connector! Any advice would be greatly apriciated, thank you!

Download the FSM from the Resiurces section. Then you can check the wiring. If it’s the wrong harness, order the right one through Davey’s or a shop on EBay. Far easier than trying to make the wrong harness work.
 
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Agree with the FSM. I think you're going to need to go wire by wire through your entire wiring harness to get this to work.

Post some pictures of the transmission so we can help identify. Hopefully it's not a AW4.

-Mac
 
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Hey I finally figured it out, po put a 2003 engine harness in, I replaced it with a 2002 numbers matching harness and everything plugged up except the transmission? The harness has 1 plug that has 4 wires but the transmission has 2 plugs on it? The 4 wire connector wire colors are purple with white, purple with black, black , and brown with blue! Am I missing a pigtail adaptor or something? Thanks
 
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Perhaps the reason they did the 2003 harness was to accommodate a different transmission? Wasn't that the year they switched from the ,32 to the 42 @hear ?

-Mac
 
Perhaps the reason they did the 2003 harness was to accommodate a different transmission? Wasn't that the year they switched from the ,32 to the 42 @hear ?

-Mac

Yea 02 was the last year for the 32RH. It’s only got 2 electrical connectors on it. A 2 wire connector for the torque converter lockup solenoid, and a 3 wire connector for the NSS. Aside from the lockup, it is not at all electronically controlled.

The 42RLE is electronically controlled so will have more wiring. I don’t know anything about that wiring.

The AW4 is another possibility, and is also electronically controlled, but this transmission never came from the factory. It shows up as a swap every now and then.

Take a pic of the trans pan so we can ID it for you.
 
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Yea 02 was the last year for the 32RH. It’s only got 2 electrical connectors on it. A 2 wire connector for the torque converter lockup solenoid, and a 3 wire connector for the NSS. Aside from the lockup, it is not at all electronically controlled.

The 42RLE is electronically controlled so will have more wiring. I don’t know anything about that wiring.

The AW4 is another possibility, and is also electronically controlled, but this transmission never came from the factory. It shows up as a swap every now and then.

Take a pic of the trans pan so we can ID it for you.

Ok that explains it! My harness is for the 42rle, and the po put a 32rh in! it has the 2 wire torque converter lockup plug and the 3 wire nss plug! What would I need to do to run the 32rh?
 
Perhaps the reason they did the 2003 harness was to accommodate a different transmission? Wasn't that the year they switched from the ,32 to the 42 @hear ?

-Mac

The harness was from a 2003, it wasn't plugged to the transmission! I put the right harness back in it but the po did change the transmission from the 42rle to the 32rh!
 
Ok that explains it! My harness is for the 42rle, and the po put a 32rh in! it has the 2 wire torque converter lockup plug and the 3 wire nss plug! What would I need to do to run the 32rh?

Update, lol! I'm confused now! My vin says it should be the 32rh and it is! Is there a pigtaill to connect the 4 wire connector on the harness to the 2 separate connectors on the transmission?
 
Hey I finally figured it out, po put a 2003 engine harness in, I replaced it with a 2002 numbers matching harness and everything plugged up except the transmission? The harness has 1 plug that has 4 wires but the transmission has 2 plugs on it? The 4 wire connector wire colors are purple with white, purple with black, black , and brown with blue! Am I missing a pigtail adaptor or something? Thanks

Good job so far. 2002 had the 32rh auto transmission. Is the transmission harness separate or part of the engine harness?

Is this the harness you have now?

https://www.ebay.com/p/14040044605
 
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Ok that explains it! My harness is for the 42rle, and the po put a 32rh in! it has the 2 wire torque converter lockup plug and the 3 wire nss plug! What would I need to do to run the 32rh?

I've re-written this response multiple times as I think of different things.

I think we need to establish what computer you have. And then somebody with more knowledge than me on the 42RLE will know how to tell if the TCM is in the PCM or an external unit. Because if you have a computer trying to control a 42RLE but you have a 32RH, I would expect that the computer is going to bark at you. IDK if there is any bite to go along with that bark.

Now the 32RH doesn't need much from the computer. I'm ashamed to admit that I don't off the top of my head know if the NSS goes through the computer, so that will need to be handled, but if your jeep currently starts up then it sounds like that's already handled. The torque converter clutch lockup solenoid (aka TCC) definitely goes through the computer, but it's not absolutely necessary but it will throw a CEL and it could run hotter at cruising speeds. Theoretically you could wire it up manually if we couldn't figure out how to make it work with the existing wiring.

================================================================

But NONE of this has anything to do with your 32RH not shifting out of 1st gear since there is no computer controlling the shifts on the 32RH. There are some pressure adjustments & throttle cable adjustments (assuming you even have those in this Frankenstein setup. And those will typically result in a very very early shift to 2nd, not a missing shift to 2nd.

On the 32RH when it wants to shift to 2nd what happens is the intermediate (aka kickdown) band grabs onto the direct drum and holds it stationary. If that band can't hold the drum for some reason, then the transmission will think it's in 2nd gear but will drive as if its still in 1st gear. The 32RH is a great transmission but it is D-U-M-B. If you continue to wind things up in this scenario, eventually it will say "ok 2nd gear is done, time for 3rd gear" and it will release the kickdown band and apply the remaining set of clutches to get 3rd gear and all is right with the world. This is precisely what sent me down the path of learning about the 32RH in the first place. My kickdown band spit the bit and resulted in everything you just read.

The kickdown band not being able to hold the drum could be the result of a few things. Easiest thing is that it's not adjusted properly. This can be done w/o even opening up the transmission; there is a bolt on the side of the case, and the FSM details this process. It could be that the band is shot, as was my case. And then it could be something more complicated like a blown piston seal or other pressure problem that's causing it to not apply. Many of those causes are fairly easily solvable, although if that band is shot the transmission is going to have to come down & get opened up. Happy to walk you through that.

What to do next? Hard to say. I would probably do the band adjustment before I did anything else. The FSM details some pressure tests you can do with the jeep on jack stands, but I've never done any of those. One day soon, though, probably. I'm going to have to do some additional reading, because I opened up the FSM for the 2002 to review the pressure test procedure, and it makes mention of using a DRB scan tool for transmission codes and also makes a mention of 4th gear on page 21-226, so I need to figure out if that's just a typo or what.


p.s. I wish I knew more about this transmission, because any question you ask about the 32RH on google returns 2 pages of content authored by yours truly. I don't have anywhere to go when I have questions.
 
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update: it also mentions an overdrive clutch pressure passage, but the 32RH doesn't have an overdrive clutch so IDK what is going on in the FSM. I venture to guess that most people never so much as glance at section 21 in the FSM, and anybody actually doing to the work is going off the ATSG guide instead. Or they read the FSM and are so overwhelmed that they just assume they are too dumb to understand it and accept any errors it has.

We've got us a mystery to unravel! Happy monday.
 
I can't chase down FSM issues right now, but the diagnosis section gives a few ideas as to the cause of a no 2nd gear situation. If you get it out on the road and can make it shift to 3rd, then you can probably rule out #1.

Regardless, you can access the governor by removing the t-case & tail housing, you can remove the valve body pretty easily to look at those valves & bores, and the front servo can be accessed once the valve body is removed. The only thing on this list of causes that would require you to drop the transmission is the kickdown band itself.

1715623239953.png



There are another potential set of causes, but this mainly overlaps with the above other than the linkage. In my experience even if you completely disconnect the TV cable it will just cause it to shift to 2nd prematurely. I've never been able to make it not upshift as a result of the cable adjustment.

1715623492281.png


I'd start with the band adjustment and see if that changes anything. Here are the steps, although you probably don't need to raise the jeep to do it.

1715623957055.png


1715623984183.png
 
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I think this is it

Can you point me in the direction to find the adapter?
update: it also mentions an overdrive clutch pressure passage, but the 32RH doesn't have an overdrive clutch so IDK what is going on in the FSM. I venture to guess that most people never so much as glance at section 21 in the FSM, and anybody actually doing to the work is going off the ATSG guide instead. Or they read the FSM and are so overwhelmed that they just assume they are too dumb to understand it and accept any errors it has.

We've got us a mystery to unravel! Happy monday.

update: it also mentions an overdrive clutch pressure passage, but the 32RH doesn't have an overdrive clutch so IDK what is going on in the FSM. I venture to guess that most people never so much as glance at section 21 in the FSM, and anybody actually doing to the work is going off the ATSG guide instead. Or they read the FSM and are so overwhelmed that they just assume they are too dumb to understand it and accept any errors it has.

We've got us a mystery to unravel! Happy monday.

I think in 2002 they changed the transmission! Some come with the 42rle
 
Can you point me in the direction to find the adapter?




I think in 2002 they changed the transmission! Some come with the 42rle

02 still had the 32RH, but regardless the oddities I'm finding are under the 32RH section. If it ever shipped with the 42RLE there would be a 42RLE section, but there CERTAINLY wouldn't be 42RLE artifacts under the 32RH troubleshooting. I'm confident saying it's an error in the FSM until somebody can demonstrate otherwise.
 
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02 still had the 32RH, but regardless the oddities I'm finding are under the 32RH section. If it ever shipped with the 42RLE there would be a 42RLE section, but there CERTAINLY wouldn't be 42RLE artifacts under the 32RH troubleshooting. I'm confident saying it's an error in the FSM until somebody can demonstrate
 
02 still had the 32RH, but regardless the oddities I'm finding are under the 32RH section. If it ever shipped with the 42RLE there would be a 42RLE section, but there CERTAINLY wouldn't be 42RLE artifacts under the 32RH troubleshooting. I'm confident saying it's an error in the FSM until somebody can demonstrate otherwise.

Looks like you are right! So I should be able to find a adaptor connector to connect the single 4 wire harness plug to the transmissions 2 plugs?
Good job so far. 2002 had the 32rh auto transmission. Is the transmission harness separate or part of the engine harness?

Is this the harness you have now?

https://www.ebay.com/p/14040044605

It is part of the engine harness! I'll check the harness numbers shortly and get back to you!
 
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