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1996 XJ 4.0 better alternator?


NAXJA Forum User
I've been doing a bit of research for a while now on getting a better alternator in my two XJ's. With a small Amp, blower motor and or headlights on the voltage dips below 13.0v and it just doesn't sit right with me. I experimented with a 120amp from a 96 grand cherokee and the fit seemed just fine. I didn't have to modify the bracket or anything. Wiring was the same as well. The pulley was a bit bigger in diameter but I just adjusted adjusted tensioner and it was golden.. Anyone have any input? It's been a few days and I've been checking the wiring and such just to take sure it's not getting hot or going to melt anything and it seems to be doing fine. The voltage gauge stays over the 14 line now which keeps me and the battery happy.
Next thing you should do is change your battery, starter, and alternator cables. It's not as hard as it sounds. I used a razor knife and cut back the loom until I got the cables out, then took them to Oreilly and approximated the correct sizes, then bolted the new ones in. Not surprisingly, the original (or one that I got with this jeep) woke up and charging has never been better.
I should have mentioned I did that previously before the alternator and battery swap. The cables had all seen better days so I started with that and then upgraded to a 35 series Optima Red Top.
There is the 136 amp from the ZJ. I did install one into my '98 XJ. Need to remove some aluminum from the bracket though. Also, might check into upgrading the fusible link. I plan to upgrade to a 4ga wire and a MEGA fuse. Others have done that. There is also a 160 amp from the 03 Dakota. I am looking into that, for a '01 XJ. Different plugs. I think they can be converted to the older style.
I have run the 136 amp for a few years, with no problem. Still, I would plan to upgrade. The other side is the factory fuse link will not flow as much as an upgraded one. So, while you have upgraded the alternator, you are not getting the full benefit.