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Everything you ever wanted to know about the AW4

Are you sure you didn't wire the NSS to the TCU harness and the solenoid harness to the NSS plug on the wiring harness? That could easily cause a no-start... wiring the TCU/solenoid harness wrong should not cause one, it just won't shift right.

I actually figured it it. you just wire the same colors together and there will be 2 wires that are left alone. No idea what they do but the jeep runs fine.

However the 4x4 light doesn't come on, i'm not even sure if 4wheel drive works, i'll look into it. It might be because of a plug at the back of the trans, by the transfer case, it is a 2 wire plug that can either plug into the transfer case or into another plug that is hanging there. I haven't followed it to see where it goes but i think it just goes back to the engine bay and then into the giant mess of wires. Anyone know about this 2 wire plug? i can take pics if needed.
 
I actually figured it it. you just wire the same colors together and there will be 2 wires that are left alone. No idea what they do but the jeep runs fine.

However the 4x4 light doesn't come on, i'm not even sure if 4wheel drive works, i'll look into it. It might be because of a plug at the back of the trans, by the transfer case, it is a 2 wire plug that can either plug into the transfer case or into another plug that is hanging there. I haven't followed it to see where it goes but i think it just goes back to the engine bay and then into the giant mess of wires. Anyone know about this 2 wire plug? i can take pics if needed.
There's a socket on the transfer case that is for the 4WD indicator switch, and one on the tail housing of the transmission that is for the output speed sensor. The output speed sensor one is important, the other really isn't.
 
If the front axle is a disconnect style, the 4wd light might be triggered by a vacumn switch mounted up on the firewall. At least that's how the older ones were setup.
 
There's a socket on the transfer case that is for the 4WD indicator switch, and one on the tail housing of the transmission that is for the output speed sensor. The output speed sensor one is important, the other really isn't.

I have the output speed sensor one hooked up right now. Shouldn't they both be pluggin in though? i'd like to see the 4WD indicator on my dash when i'm in 4WD. I don't remember there being an extra plug on the old tranny?

Also mines a 97, so no vacuum.
 
The plug for the 4wd indicator is actually on the transfer case, not the transmission. Let me see if I can find out how you're missing the plug for that... my bet is that the cable and plug got tangled up behind/on top of the transmission during the swap.

EDIT: Think I figured it out. You probably have two plugs that can plug into that now - one from the harness that also handles the rear O2 sensor and the VSS, which leads to a 10 pin connector up near the connector you spliced for the transmission solenoids and speed sensor (this is the plug you want) and the other that's built into the harness that came with the 96 AW4 (which goes nowhere, and is the extra wires you mentioned when asking about the butt splices.) Not sure how I missed that in the writeup, especially since I used to own a 96. Try the plug that's on the harness going to the VSS and O2 sensor, it might be hidden up behind the transfer case or transmission after the swap.

I'll update the first post, thanks!
 
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Alright I just wanted to start out saying thanx for all the great information on the AW4.

Now my question is I have a 96 Cherokee Classic with a AX-15 And it is going down hill fast needs replaced. I also have a 89 Cherokee Laredo as a parts jeep. With a good working AW4 With the power/comfort switch. I read were it will bolt up and can be used. What im asking is what all do I need to pull out of the parts jeep besides the AW4 Tranny, wireharness, Power/comfort switch, TCU, and swapping the input shafts on the transfercase or just swapping the tranfercase altogether? Do I need any thing else? Does the TCU get wired to ECU in anyway? Or do I need to splice into anything? Or is it just all plug and play and no splicing? Any help will be greatly appreciated.

Thanx,
 
Since 89 to 96 swaps across the 94.5 line for the transfer case input gear helical pitch *and* the 95 to 96 transfer case tailcone seal style change, you're going to have to swap in the AW4, transfer case, AND rear driveshaft... but AX15 vs AW4 have different driveshafts, so you're going to need to find an 87-95 4.0/auto/4wd rear driveshaft from a donor with the same rearend as you, and a front driveshaft from any 4.0/auto donor. I really wouldn't do this swap, it's opening a pretty big can of worms mechanically. You will also need the transmission crossmember and AW4 shifter + cables from the donor, possibly a TV kickdown cable from a 91-01 AW4 (not sure if the RENIX style TV cable connects to the throttle body on a 91+ the same way or not), and I'm sure I'm forgetting some other stuff. Oh yeah, trans cooler hoses as well.

The electronics are going to be interesting, you will want to find a 91-96 TCU and wire it in, since your TPS is the OBD style the 89 one may or may not work. It will involve a lot of splicing since your harness doesn't have any of the connectors for the TCU, might be missing contacts in the brake light switch, doesn't have the wiring for the TPS to TCU connection, the NSS, the trans sensor+solenoid harness, etc.

If you can find a 91-96 donor with 4.0/auto/4wd/same rearend as you, the swap will be much easier (you'll need trans, transfercase, driveshafts, and support parts for the trans), but will still involve a decent amount of wire splicing.

I would really just try and beg/borrow/trade another AX15 off someone, or rebuild yours. What's wrong with it? If it is just the synchros you can get all the ones you need off quadratec for around 100 dollars and maybe throw in some bearings for another hundred or so. I haven't ever rebuilt an AX15 but am hoping to pick up a spare to rebuild soon.
 
i'm curious, if i don't have the power/granny switch from factory, would the transmission just be defaulted to granny mode? also, would i simply be able to add the option by finding the pigtail behind the dash and adding the switch? or perhaps bypassing it, like i saw mentioned in here before?

1994 XJ
 
I'm not sure if a 94 even has a place to plug the switch into the harness, and pretty sure the TCU is blissfully unaware of the feature ever existing. You'd need to swap in an earlier TCU that supports it and wire the switch to the proper pin.

All I ever did with my power/comfort switch was bump it into comfort mode by accident with my knee while 300 miles from home and panic, thinking my 200k+ mile AW4 had just started dying.
 
oh i see, doesn't really sound like something worth doing if there are no really notable performance gains other than feeling a slightly harder shift

i'm not really sure of the pros/cons of power vs comfort right now anyways so i don't see all that wiring to be all that beneficial at this point
 
Hey thanks for the fast reply, I believe my synchros are gone. Can Hardly ever get it in and out of gear, and the only way to get it into reverse is I have to shut off the engine put it in reverse and then start it back up. Plus another reason for wanting to swap in the AW4 Is that I HATE trying to wheel with a 5-speed just constantly on the clutch and gas and break all at the same time pretty much trying to crawl over rocks is not fun. I was hoping it wouldn't be all that hard to swap over since I have all the parts in the Donor Cherokee. The transfercase in the donor Cherokee has a slip yoke eliminator already on and has a rear tom woods driveshaft if that helps any. I really didn't want to have to go and buy another transmission from a earlier year at the junk yard since I already have a good one in my parts jeep.
 
What you're describing with the manual trans does not sound like synchros. It sounds like incomplete clutch disengagement possibly caused by faulty clutch hydraulics.
 
im just guessing on most of this anyways, i just put a clutch master/slave and a new clutch in an old yj we have at work designated "the mule" we use it for hauling, and man was that old clutch ever soft

intermittently it would also not go into any gear, unless of course it was "coaxed" in
 
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