[Jeds Sr.]

I have an 87 Cherokee and my old alternator died so I wanted to try the high output alt mod. So I found an alternator at the junk yard and the alternator bracket on e-bay. One other little thing is different, the plug with the two small wires. I'll have to attach my existing wires on the new alternator but I don't know which one to put where. I guess I have a 50/50 chance of getting them right There are two wires, one has 12v when the switch is on, the other wire doesn't show anything. Any ideas how I could finger out which wire goes where

(no I didn't forget to run 4 gauge wire )

thanks for any info

[Jeds Sr.]

I guess there are no takers on this subject It's ashame that I've been doing mechanic work all these years but I'm not sure what the small wires are for on an alternator.

Alright, I'm going for the 50/50. Well maybe it's a little better than 50/50. I took the alternator to Advance auto to have it tested and noted where they put the green lead and the black lead from the tester. I assume (and hope like heck) the green lead is where my 12v supply should be.

Nothing to loose but 60 bucks

[Jeds Sr.]

Ok, one of the wires has to be for the Alt guage.........


ok Jed, stop spamming this string

[Jmila1901]

i think things are different on your vehicle... i read somewhere that the newer xj's have computer controlled alts and the old renix ones have self controlled alts

[Jeds Sr.]

Thanks for the response Jmila1901. If that's the case, I may be in trouble + have wasted a bunch of money .

Since I'm not sure, I'm going to keep trying to make it work. Most alt's are enternally regulated, I'm still hopeful this one is.

Couple of updates, (1) the alternator bracket I bought from a 95 Cherokee didn't fit the 98 Dodge alternator very well, had to grind the crap out of the bracket.
(2) My old belt was way to long so I purchased a belt for a 1995 Cherokee and it worked.
(3) The alternator isn't charging


If you want to know the basic workings of an alt, this is a good artical.
http://jeep.off-road.com/jeep/article/articleDetail.jsp?id=376201

I know I'm not getting many responses but this has to help someone one of these days. Before it's over, I may even make the sticky section
(or the what not to do section )

[Jeds Sr.]

It looks like the Dodge alternators are controlled by "powertrain control module" and do NOT have a voltage regulator!

I think this link seals my doom on this project.
http://www.dodgeforum.com/m_610883/tm.htm

BTW the Mid 90's Jeeps must have a Control Module of some sorts to make the alternator work. Does anyone know what it is?

I'm still going to check the alternator shops tomorrow just as a last ditch effort.


(I'm about ready to put a rat in a round cage and let it run round and round )

[Jeds Sr.]

Got it !!!!! You too can do the 136 alt mod on your older XJ and you won't believe the difference!!

It's not a direct bold on like the 93 and up xj's, here is what you need:
(this is just an add-on to the 136 amp alternator mod that is in tech tips so you old xj owners can join in) http://www.bc4x4.com/tech/2004/jeepalt/

97 or 98 Dodge 136 amp alternator serial # 56027913
Alternator bracket from a 93-98 4.0 engine (I had to grind the bracket some)
Alternator belt from a 95 xj
External voltage regulator for a 1985 Dodge puck-up
14 or 16 gage wire
#8 nuts (attach the wires to the back of new alt)
sever little wire connectors

Other info:
The new alt is hard to get in, not much room. I had to attach my alternator to the bracket and put in both at the same time.

Wiring in the voltage regulator....
You have two small wires running to your old crappy alt (not counting the big wire that runs to the battery), one is from the switch and supplies 12V with the switch on. The other goes to your light/gage. You'll have to cut the old plug off and put on the round connectors on each wire.
The voltage regulator has two pins, (Advance auto part # VR295). Run a wire from the VR center pin to connect with the existing small 12V wire, attach both to the bottom alternator terminal with a #8 nut. Run a wire from the other VR pin to the other alternator terminal and stick the existing light/gage wire on with it, attach with a #8 nut.

In a nut shell, your two existing alternator wires will attach to the new alt plus two new wires from the VR. Just make sure the center pin in the VR attaches to the wire that supplies 12V. Matter fact my VR came with a wiring diagram
http://www.partsamerica.com/product_images/aap/gps/gps_vr295_terminal.jpg

I mounted my VR on the fire wall near the battery. I also ran an additional small ground wire from a bolt that holds the VR down to the alternator. Everything I read says grounding the VR is very important.

Several parts to buy, check prices and make sure it isn't cheaper to upgrade your old alt.

[balloo93]

Man, very nice. This is going to help out more people than you know (including a buddy of mine who bought one then realized it wouldn't work!). I will add this to the Tech sticky.

[Jmila1901]

Slick bro! great job! Just wondering is the Cherokee starting up any quicker?

[Jeds Sr.]

Yes it's starting better BUT, I had to put a new positive cable from the battery to the starter so that may be why. I can't believe the difference it made on everything else. My old alternator must not have been doing much.


(I made the sticky section, cool )

[ehud6342]

Thanks for the posting, I just got this going in my 70' J-2000. It works great, I would never have got it running without this info.


Sean

[rockershocker88]

pictures of how u wired it up? im in the middle of doing this swap and think i may have hooked it up wrong

[RacerX]

Pics? !!
Also are there any alternators like this with a built-in regulator that will fit?

[RacerX]

Anyone Know what high-power Alt I can use on a 1989 (Renix - I guess)
I need a good 100Amps, or so. 1000W inverter + lights, amplifier..

[btoohey44]

Originally Posted by RacerX

Anyone Know what high-power Alt I can use on a 1989 (Renix - I guess)
I need a good 100Amps, or so. 1000W inverter + lights, amplifier..

Pretty Expensive but it's there

RockAuto has this 100amp in stock

Hope it helps

2E