Stock Alternator Output??

mtnbikermatt · **Joined:** Sat Mar 17, 2007 9:29 am **Posts:** 66

I have a 06 liberty with the 136 amp alternator, I currently have it wired with 65 watt fogs, 2 hella 500's on grille gaurd,
when the high beams are on the hellas and the fogs stay on and it dims at idle, will it fail if I put four more hellas on it?

MiniDevil · **Posted:** Sun Feb 03, 2008 7:25 am

The factory electrical powerplant sucks. The battery is not meant for cycling at all, and the alternator puts out just enough power for the vehicle. I'd say to upgrade it. I am in the process of upgrading myself. I couldn't even charge my 65w laptop with an inverter at idle for an hour without the inverter alarm going off saying low power input.

madlarkin · **Posted:** Mon Feb 04, 2008 1:33 am

I have heard rumblings that the Renegade has a 160amp alternator and is a little less pathetic in the charging department, is this true? I am just wondering if I lucked out. Otherwise its off to a HO alternator and a battery bank(if I can find the space

)

Maximum Carnage · **Posted:** Mon Feb 04, 2008 10:56 am

madlarkin wrote:

I have heard rumblings that the Renegade has a 160amp alternator and is a little less pathetic in the charging department, is this true? I am just wondering if I lucked out. Otherwise its off to a HO alternator and a battery bank(if I can find the space

)

Correct the Renegades have a 160 AMP

mtnbikermatt · **Joined:** Sat Mar 17, 2007 9:29 am **Posts:** 66

well I just finished with my light bar and it seems to power it fine with a but of dimming at idle

Frostednutz · **Posted:** Tue Feb 05, 2008 3:21 am

even though the alternator is rated at 160 amps or 136 amps it doesn't state at what rpm or temperature. so when you're sitting at idle you're not getting 136 amps like the alternator is rated at but more like 30-40 at best. i had mine custom made and puts out a decent 100 at idle. you could invest in a smaller pulley which would spin the alternator faster but would greatly reduce the lifespan. if you really need the power you should have one made.

tjkj2002 · **Posted:** Wed Feb 06, 2008 11:33 am

Mean Grean alternators makes a 202amp alternator for '02-'05 3.7 V-6 KJ's,part# MG1387.

I have the stock 136amp alternator and I have the Renny light bar,2 KC HID lights,Warn XP9500 winch,and a 750watt amp powering two 10" subs.I can run all of my lights and stereo with the headlights and fogs on(which are 100watt 9005 bulbs) and get no dimming.The key is a good battery also,I run a Optima Yellow top,the Red Top is also a very good choice.136amps is more then plenty unless your running a insanely huge stereo and your heated seats(the biggest robber of amps),I have never had a problem with starting even after blasting the stereo for over a hour with the KJ off.My '84 F-150 only came with a 55amp alternator,now that sucked with 9 KC 130watt DayLighters,it would kill my engine unless it was turning at least 2000rpm when turning all 9 on at the same time.

mtnbikermatt · **Joined:** Sat Mar 17, 2007 9:29 am **Posts:** 66

My liberty is an 06' so will that alternator fit?, if i let my jeep idle with all 10 of my lights on it runs fine but the battery light comes on after about a minute.
what would you recommend to get first, the battery (yellow top) or the alternator?

thanks
-Matt

tjkj2002 · **Posted:** Wed Feb 06, 2008 7:59 pm

mtnbikermatt wrote:

My liberty is an 06' so will that alternator fit?, if i let my jeep idle with all 10 of my lights on it runs fine but the battery light comes on after about a minute.
what would you recommend to get first, the battery (yellow top) or the alternator?

thanks
-Matt

It may or may not,it will bolt up but the wiring may be different,may need to call Mean Green to varify.I would get the a good battery first.Like I said I can be running my headlights,fogllights,Renny light bar,2 KC HID's,and have my stereo(750watt amp and two 10" subs) cranked up at idle with zero dimming of any of the lights or anything and I'm running the stock 136amp alternator and a Optima Yellow top.

mtnbikermatt · **Joined:** Sat Mar 17, 2007 9:29 am **Posts:** 66

thanks tjkj2002 I am going to get the yellow top first thing tomorrow

WoodysKJ · **Posted:** Thu Feb 07, 2008 10:47 pm

The meangreen 202 MG 1387 should fit the 06. Unless chrysler changed things in mid year of 06-07.

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=28674

I tried the MG1387 in my 07 and discovered the change in the plug and wiring to the PCM.

In your 06 it should be fine. BUT....

The way the PCM and the alternator in the KJ work together is a bit screwy.

Long and short of it is there is a temp sensor located under your battery. when that sensor reads a certain temp it tells the PCM to allow the alt/gen to fire up and charge the battery. It took me a while to understand Troy's recomendation to put in a yellow top.

Your lights are going to run, if wired properly, off the battery FIRST. as they deplete the battery the PCM tells the alt/gen and it voltage regulator to run at higher levels to charge the battery. SO the Alt/gen in your KJ is capable of running at 136 or 160 amps. but it rarley does. At idle if your battery is close to fully charged the alt/gen can run at closer to 50% of rated capacity.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Is replacing the alternator as easy as it looks, or am I missing something? I have a 160 amp sitting here, and it looks like it's 3 bolts, a wiring harness, and the wire going to the top. Anything to worry about besides disconnecting the battery so I don't get fried? Also, is there a red top or yellow top for an early '02?

tjkj2002 · **Posted:** Sat Feb 09, 2008 7:10 pm

KY Liberty wrote:

Is replacing the alternator as easy as it looks, or am I missing something? I have a 160 amp sitting here, and it looks like it's 3 bolts, a wiring harness, and the wire going to the top. Anything to worry about besides disconnecting the battery so I don't get fried? Also, is there a red top or yellow top for an early '02?

It's as easy as it looks,nothing else to worry about after disconecting the battery.They make the smaller Optima's but they are very weak because of the smaller size,I just trimmed the battery tray to fit the group 34/78 Optima,trimmed the side of the tray(cut off) closest to the fender(don't cut the otherside,the battery will slide off the tray).

matthewheld · **Posted:** Sun Feb 10, 2008 2:17 pm

I just replaced my alternator with the 160 amp version (I don't think I would have done this had I read this discussion, however), and while examining the old alternator, I discovered that the pulley is almost freewheeling. I would have taken off the pulley to see what the explanation was, but the pulley/shaft setup looks like I'd need a special tool to do so.

Anyone have an explanation for this? If it was 10 years ago, I would have said the shaft key is gone. I can stick a screwdriver in the vents to hold the armature still, and with some resistance, turn the pulley.

tjkj2002 · **Posted:** Sun Feb 10, 2008 2:24 pm

matthewheld wrote:

I just replaced my alternator with the 160 amp version (I don't think I would have done this had I read this discussion, however), and while examining the old alternator, I discovered that the pulley is almost freewheeling. I would have taken off the pulley to see what the explanation was, but the pulley/shaft setup looks like I'd need a special tool to do so.

Anyone have an explanation for this? If it was 10 years ago, I would have said the shaft key is gone. I can stick a screwdriver in the vents to hold the armature still, and with some resistance, turn the pulley.

It's got a "one-way" bearing on that pulley,locks up when turning in one direction and free-wheels in the other.

matthewheld · **Posted:** Sun Feb 10, 2008 2:35 pm

I was just editing my last post when I read the reply. I verified that fact just now. Thanks TJ.

So, I have a rebuilt 160 amp alternator in the vehicle that I paid $366.04 with tax and a $105.00 core charge from NAPA. I could return the core and only have paid $237.89 + tax = $253.95

That's a difference of $112.09 to keep a working alternator with 90,000 miles on it. Should I return for the core charge, or keep it?

matthewheld · **Posted:** Sun Feb 10, 2008 2:56 pm

FYI - when I rechecked my old alternator I found a test sheet for the new alternator in the box. I can't find the power supply to my scanner, so I'm typing in the specs as they appear on the sheet:

JBT-5P TEST REPORT

Part Number :13913
OEM Part Number :N/A
Rated Output :160
Rated Voltage :12
Built in regulator :N
Ground system :N
Plug Number :363

PASS TEST RESULTS:

Maximum Output [A] : 169
Regulator Set Point [V] : -
Turn On Speed [RPM] : 2095
Output @ 2300 RPM [A] : 30
Output @ 5000 RPM [A] : 137
Leakage Currant [mA] : 0
Field Current [A] : 6.4
Ripple Current [A] : 4
Stator Voltage [V] : 0.1
Secondary Regulation [V] : -
Lamp Status [-] : OFF=> OFF
Active lamp [-] : NO

There's also a diagram of the plug with F1 and F2 labels, and a performance curve chart up to 6000 rpm.

GPR65 · **Posted:** Tue Feb 19, 2008 10:06 am

when it is rating output at a certain rpm that is not engine rpm is it it is the alternators rpm correct?

matthewheld · **Posted:** Tue Feb 19, 2008 11:06 am

Yeah, that would be at alternator shaft rpm. The other thing interesting is that the old alternator had the one-way pulley, and the 160 amp has a solid, standard pulley. I wonder if it was a cost-saving step in the rebuilding process to put a standard pulley on, or does the Renegade alternator use a solid pulley setup normally?

Stock Alternator Output??

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