ZJ 136A alternator into 4.0 RENIX XJ.
 

Ok here goes...

PARTS LIST:
*V8 ZJ alternator
*Brackets & hardware off of an HO XJ (I used the brackets off of a '96 XJ. No grinding was needed!)
*A voltage regulator. (part number VR101)
*A new belt off of a '91 4.0L XJ
*A 48", 2 gage, bolt to bolt ground. (part number GW249B)
*A 12' roll of 10 gage wire.
*An assortment of electrical conectors, & heat shrink.

Once you've collected all your parts, the first step should always be disconnecting your battery!!! Then test fit the alternator in with the HO brackets. Yours may need some grinding of the brackets and/or the timing cover. It should look something like this...

https://www.cherokeeforum.com/member...1-imag0440.jpg

Starting on the wiring you should follow this as to not get my words bellow mixed up.

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Now pull it back out, & take this connector off the back. (if your like me you cut these wires at the junkyard)

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Use a hacksaw to cut the 6 gage wire out of it.

https://www.cherokeeforum.com/member...0-imag0451.jpg

Add another eyelet to the other end, then connect one side to either field terminal on
the alt. (doesn't matter witch) Then the other end to the housing of the alt. along with the 49" 2 gage ground wire thats ran to the block in the same place the battery is grounded. (some might say this is over kill, but I like to know its well grounded)

https://www.cherokeeforum.com/member...1-imag0452.jpg

Now run the length of 10 gage wire from your fuse boxes open terminal labeled "ign". (12V ignition wire.) Sorry no pic of this, but a male flat wire connector will plug strait into the "ign" slot. Now route it threw the firewall, across to the passenger side, up close to the battery.

Get your new voltage regulator out of the box. Pic doesn't show the same part #, but I told the kid at checker I needed part # VR101. This is what you should end up with...

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Mount the voltage reg. where ever you like it. It will have two terminals, one of which is labled "ign" (believe its the one on the left of this pic.) You guessed it, the "ign" wire from your fuse box will plug in here.

The connection on the right will go down to the second field terminal with a short length of your 10 gage wire.

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I also ran this wire to the housing of the voltage reg. (agiain for good measure.).
https://www.cherokeeforum.com/member...2-imag0501.jpg

I'm curently using the factory power wire/fusable link. It has not been changed at all as you can see here...

https://www.cherokeeforum.com/member...3-imag0503.jpg

Now I do alot of crawling on hard slow pace trails, so voltage output at idle was more my concern. After hooking up the alt with the ZJ pulley under full draw (all accessories on) It was putting out 12.5V at idle. I desided it needed the smaller pulley from the XJ alt. Swapping them out was a bit of a task!
The Xj alt uses a allen into the alt.s shaft, then I used a O2 sensor socket to loosen the nut. The ZJ used the same O2 sensor socket, but has a (I believe) 10mm head on the alt. shaft. I had to add a thin washer that came off of one of them between the ZJ alt. & XJ pulley, so the pulley didn't rub on the alt. housing. I got the nut tightened on the shaft, but couldn't really get on the 10mm shaft. a little JB weld to the nut from backing off... JB weld fixes EVERYTHING! lol :laughing: Note: See I didnt use the XJ pulley fan.

https://www.cherokeeforum.com/member...5-imag0479.jpg

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The pulley swap isn't needed for rigs that dont do alot of night crawling, slow speeds, ect. The ZJ pulley works fine as is, but has an 6th groove for the ZJs wider belt. It wont affect how it rides on the pulley, just sets farther forwardthan the factory alt. did. see

https://www.cherokeeforum.com/member...8-imag0468.jpg


Go ahead & bolt it back up in there, hook up wires, & run the '91 XJ 4.0L belt around all that mess that it the 4.0L.

As you can see your old belt is now way to large, yet I also tryed a '96 belt, which was to short. The '91 fits just right.

https://www.cherokeeforum.com/member...2-imag0469.jpg

Heres the belt I used for the '91 XJ.

https://www.cherokeeforum.com/member...3-imag0476.jpg

As for the factory alt. plug... you can cut those tan & yellow wires, & cap them off!

Once its all hooked up, reconnect your battery. Get a voltmeter hooked up to the battery terminals, & start the jeep. You should be getting 14.5V-15V max to your battery weither your at 2k-3k rpm. this means the regulator is doing its job. If not double check that the ignition terninal in your fusebox is putting out 12v. At idle with full draw the system shouldn't drop bellow 12.5V. If your between those two it is in proper working order :D Congrats!!!