^Agreed.
Sorry to yet-again-revive such an old thread, but I have one more thing I need to know about the AW4.
I am about to put an AW4 into a CJ7 and want to use full auto shifting or manual. I have an option to get a good '99 XJ AW4 REALLY cheap. I will have to get the harness and TCU from a JY. Can I use the '98-01 AW4 with 90.5-97 harness and TCU if using entire harness and TCU, or still need the "adapter" circuits listed? Should I hold off until I can get either a 90.5-97 AW4 or a 98-01 harness/TCU, or can it easily mesh?
I know the first post addresses mods, but is that different if I use entire harness/TCU?
Finally, is the harness integrated into the Jeep's overall harness, or still stand-alone? I have gotten mixed info online in reference to this.
Thanks
Cool project! I did a 4.0L EFI into a '73 CJ5 for a friend's dad a few years back, but we converted to manual using the stock T150 or whatever it had (think it was a T150 but not sure) rather than swapping the AW4 as well. Had to use the Hesco front mount CPS conversion kit since the AX15 EFI notched flywheel and CPS mount bellhousing wouldn't work with the T150 without a lot of fabrication work.
In order:
- if you want to use a 98-01 AW4 with a 90.5-97 harness and TCU, you will need the adapter circuit, OR to swap the tailhousing, OSS, and OSS magnet rotor. If you get the 98-01 TCU and harness pigtails for it and the trans+other stuff, you need no adapter circuit.
- I would probably hold off till you can get a matching setup. If you need a 98-01 TCU and the harness pigtail for it, I am sure someone on your local
chapter classifieds is probably parting out an old rig and no one ever buys those parts, so they are probably still available.
- if you use the entire harness and TCU you can ignore most of the stuff I mentioned except spline counts and stuff like that. Reason being, all your stuff is coming from the same donor, so it should Just Work, basically.
- the harness is integrated into the XJ's harness. You have two options, gut the donor XJ's harness, strip all the loom and tape off and start splitting the trans-related stuff from the engine/body related stuff and it becomes pretty obvious what you will need. By the time you are done you will probably have a chunk of harness with some wires hanging out for SCI bus, CCD bus, brake lamp sense, TPS signal, ignition power, constant power (I think? can't remember if the TCU has this pin), and ground, maybe plus another few signals I am forgetting. At that point you splice it into your CJ's harness however you want. You can ignore the SCI and CCD buses, they're mostly for diagnostics and ECU comms and won't be necessary.
Stuff you didn't ask, but came up in my mind while I was answering your questions:
- remember that the AW4 TCU is going to want a TPS signal. If you haven't EFI converted your CJ7, you probably don't have a TPS and this is going to get interesting since I don't know how to mount one to a carb. It may be easy, it may be hard, I'm not sure, I'd look into using an 87-90 automatic 4.0L XJ/MJ TPS since they have a little flapper arm that can probably be rotated by the end of the carb's throttle shaft if you find a way to mount the TPS, and they have easier to source GM Weatherpak connectors. I'm not 100% sure that the TPSes for HO and RENIX are the same resistance/voltage curve, but I would be rather surprised if they aren't all linear and it's just a matter of setting the right 0% throttle reference voltage by adjusting the TPS's position.
- Make sure you get the right spline count AW4 so your tcase bolts to it nicely. IIRC, a dana 300 has 23 splines, if you don't have the round bolt pattern and instead have the texas bolt pattern it might get interesting to attach the two. If you have the round pattern, a simple clocking ring generally used by XJ enthusiasts to put CJ7 D300s into XJs should do the trick nicely.
- It's too bad you're a thousand miles away because this kind of project is something I find fun. If you were up here and had electrical issues with it I'd say drop on by with some beer and we'll make it work.
- If you don't feel like gutting the donor's harness at the junkyard or can't for one reason or another, just make sure you get pigtails for each connector (NSS, trans sensors+solenoids, TCU) with 6+ inches of wire included. At that point you can very easily splice up your own harness that connects them all together working in the shop, it's pretty self explanatory and mostly just color matching. If you need wiring diagrams with color codes for your eventual donor's specific model-year, let me know and I'll find them.
edit: I know for a fact I have a 97-down style OSS and 4x4 AW4 tailhousing sitting in my upstairs hallway right now, and assuming I do the 4x4+5-speed conversion on my 88 MJ soon, will have a donor for the rotor and its snaprings. If you want them, they are yours for the price of shipping (payable upon receipt), but I can't guarantee when I'll be doing the MJ's swap or how long it'll be before I remember to ship stuff to you.
