Alternator options

mbalbritton

mbalbritton

#@$%!
Joined
Mar 22, 2005
Location
Orlando, FL
School me on Alternator options.

What are my options on alternator hen going from an '87 258 to a '94 4.0? I also plan to move over to electrical cooling fan so if I need to be considering an upgrade beyond what I'm already going to be gaining, now is the time. but going from 56amp to 90amp is pretty good for my set up. no winch or stoooopid big stereo system to worry about.

I'm looking to understand the wiring from my OE harness and the voltage regulation to the more modern alternator. So, What do I need and how do I wire it?
 
See if you can find a gm 1 wire alternator that bolts on, or you’ll need an external regulator if you use a jeep one and don’t want to use pcm control. They’re like 15 bucks but only need switched power to work without being controlled by the pcm. Work with any alternator from efi jeeps that has 4.0

1781537183043.png
 
ok, so install an external regulator like the VR-125. that lead me down a rabbit hole of info. I found several options for a regulator, none of which were $15, but that's ok. :) Looks like installing one of many options of regulators and then possibly upgrading the battery cable and inline fuse. seems fairly straight forward.
 

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Of course the price has gone up…

It is a simple system, drop below 12v charging, go over 14 stop charging rinse and repeat

as opposed to pcm control that says we are cruising let’s trickle charge, accelerating hold off for now, it changes based on throttle demand
 
mbalbritton said:
ok, so install an external regulator like the VR-125. that lead me down a rabbit hole of info. I found several options for a regulator, none of which were $15, but that's ok. :) Looks like installing one of many options of regulators and then possibly upgrading the battery cable and inline fuse. seems fairly straight forward.
Click to expand...
You only need a fused 12 volt wire that is part of the key on circuit for these to work, I’d put a heavy gage wire from the alternator to the starter terminal or straight to the + side of the battery from the alternator
 
All Chrysler alternators were pretty much interchangeable from the eighties to the mid 2000s if I'm not mistaken. I've got a 160a from a 2002 Durango in a 94 2.5 xj. A little wiring upgrade and blam!

Durango Alternator Swap Compatability

Does anyone know what years of Durango alternators are compatible with which years of XJs? Is there a list anyone has put together? For mine, I have a 1996 4.0L HO and I'm looking at a 2002 Durango with the 5.9L which should be the 160amp alternator (12329 at Autozone)
naxja.org naxja.org
 
20+ year old article is still as relevant as the day it was written...

 
Shreddinlettuce said:
See if you can find a gm 1 wire alternator that bolts on, or you’ll need an external regulator if you use a jeep one and don’t want to use pcm control. They’re like 15 bucks but only need switched power to work without being controlled by the pcm. Work with any alternator from efi jeeps that has 4.0

View attachment 457896
Click to expand...
Finally got around to grabbing a regulator.

In that diagram the Blue from Power module wire, what is the power module it speaks of?
 
mbalbritton said:
Finally got around to grabbing a regulator.

In that diagram the Blue from Power module wire, what is the power module it speaks of?
Click to expand...
12v switched power pretty much any circuit from the fuse panel but a lot of oem applications tie it into the horn relay. Needs 12v with the key in run and start position

It feeds the electromagnet of the rotor so 15 amp fuse will be enough
 
Using the Chrysler alternator, two wires coming from the regulator. There is a ground wire connection on the back of the alternator. Is this needed to run to a ground, or is the alternator case grounding enough?

And I take it that the exciter wire that the old alternator used is no longer needed because of the new external regulator.
 
mbalbritton said:
Using the Chrysler alternator, two wires coming from the regulator. There is a ground wire connection on the back of the alternator. Is this needed to run to a ground, or is the alternator case grounding enough?

And I take it that the exciter wire that the old alternator used is no longer needed because of the new external regulator.
Click to expand...
I would ground to the battery and engine block from the stud on the alt.
 
Jeez I hate this crap…

Now the positive to the battery. I have the OE wiring from the ‘87 as well as the ‘95 donor. I’m using the ‘95 alternator.

How do I determine or what gauge wire should run between alt and battery and does it need a fusible link? The one on the ‘87 is shot and good thing it’s being replaced.
 
mbalbritton said:
Jeez I hate this crap…

Now the positive to the battery. I have the OE wiring from the ‘87 as well as the ‘95 donor. I’m using the ‘95 alternator.

How do I determine or what gauge wire should run between alt and battery and does it need a fusible link? The one on the ‘87 is shot and good thing it’s being replaced.
Click to expand...
The bigger the better, measure the length you need and get that length from the battery cable selection at an auto parts store. Especially if you’re running a winch larger cable will heat up less. You can use a fuse or circuit breaker (like 200 amp) from the car audio section if you want, but it’s not necessary
 
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