What size fuse for 200 amp alternator - JeepForum.com
LinkBack Thread Tools
post #1 of 4 Old 08-22-2013, 11:13 AM Thread Starter
Registered User
Prot's Avatar
2014 JK Wrangler 
Join Date: Feb 2007
Location: Lafayette
Posts: 8,080
What size fuse for 200 amp alternator

I am upgrading the charging system on my 2007 JK. I am going with dual batteries and a 200 amp alternator from Mean Green. While I am at, I am doing the big 3 upgrade.

I have been researching the various aspects of this as I slowly gather all the parts. My JK is my only vehicle and I live quietly alone, hence all the planning.

I am going to replace the positive wire that goes from the alternator to the battery. It currently has a fusible link. I am replacing this wire due to the higher output alternator and of course, will need to have an inline fuse.

I was only able to find one source so far on another forum where this fuse is specifically mentioned and the guy used a 300 amp fuse.

Does that sound right? I don't want to use a fuse that is too big and something go wrong, causing everything to melt as well as cause other damage. On the other hand, if the fuse is too small, it will blow constantly.

I was also hoping for somebody to point me in the right direction for a high quality fuse. I am hoping to get this done right the first time and put an end to my electrical woes.

2014 JKU Copperhead Pearl
Too many mods to list. Too awesome to sell.
Prot is offline  
Sponsored Links
post #2 of 4 Old 08-22-2013, 12:39 PM
Registered User
1995 XJ Cherokee 
Join Date: Oct 2007
Location: Whitesburg
Posts: 5,293
I am not an advocate of a so called "high output" alternator.

The amperage the alternator can output is directly related to the size of the windings, rectifier, and the amperage rating of the rectifier diodes.

Most late model alternators are so tightly packaged into their cases (unlike the GM CS alts) that there is physically no more room in the case to upgrade the components.

So unless you find an alternator manufacturer that is building an alternator in an aftermarket case you are being fooled by them posting peak amps and not rated continuous amps.

Let's for a minute say that your alternator is capable of outputting 200amps continuous, and that the load on your system is the same (200amp) that would mean the required gauge wire would be somewhere in the 1awg or 0awg range to successfully sustain that amp draw.

My advice is to do the dual battery setup with a good isolator and keep your current OEM alternator and wiring in place. The added reserve capacity will do you much more good than a "high output" alternator will ever net you.

95' XJ Country - Stock Skids - D30/D35 Limited Slip - 3" Lift - 31x10.50R15 - 4.0 HO - AX15 - NP231

98' XJ Classic - D30/C8.25 - 4.5" RC Lift - 33x12.50R15 - 4.0 HO - AW4 - NP231
Originally Posted by Azzy View Post
You can tell the character of a person in how they treat someone who can do nothing for them.
Holder350 is offline  
post #3 of 4 Old 08-22-2013, 01:00 PM Thread Starter
Registered User
Prot's Avatar
2014 JK Wrangler 
Join Date: Feb 2007
Location: Lafayette
Posts: 8,080
Mean green is a reputable company and has been building high output alternators for jeeps and other vehicles for years. The idea that Jeep or any other automobile manufacturer is building them at the highest capacity or quality is ludicrous. The stock alternator on a JK puts out 160 amps. The replacement puts out 200 amps. It is not outside the realm of reason that a 40 amp increase is possible with this type of alternator.

I am not here to debate the merits of the alternator I have purchased. I thought I would seek some helpful advice on fuse selection. I just sent an email to mean green asking them for advice.

2014 JKU Copperhead Pearl
Too many mods to list. Too awesome to sell.
Prot is offline  
post #4 of 4 Old 08-23-2013, 02:53 PM
Registered User
Join Date: Jun 2012
Location: West Springfield
Posts: 155
I agree with holder350 on using 0awg. As far as the fuse I recommend using an ANL style fuse. And the size should reflect whatever the max output is on the alternator. It will most likely never reach it's peak. And in the rare occurrence it does you will be protected. I would not recommend using any type of circuit breaker or any thermal switching circuit that you can reset. These usually have greater tolerances and are not as safe and reliable.
wjguru86 is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome