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Alternator charge wire???

H

hereismylife

formerly j k auto
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pa
I was looking at my charge wire on my alt ( alt to the batt wire). I was thinking of upgrading it so it has a better flow to the batts. Well I do remember seeing somewhere that there is a resistor in the wire.

What does that resistor do? Can I replace the wire without it?:confused:

thanks
 
Uh-Oh. When I replaced my engine last year, I also did all of the cables. But I didn't know about the fusible link. I read that thread link, but it seemed like the guy "added" a fusible link, meaning there wasn't one there from the factory. Is there a fusible link from the factory?
 
yes, gm puts several fusable links in. the one for the battery to alternator is inline and looks like a bulge in the cable. Just in case something shorts out its there to keep from creating a fire or blowing a battery. could be a 90 or 135 amp fuse(I think that was the amperages the alternators came in). whaterver amp, the fuse needs to be rated at the gauge of wire used.
 
(Joe, sorry to steal your thread a bit, but seems like I have the same question as you)

OK, I've never looked to buy fusible link or a stand alone, in-line 135 amp fuse before. Which is the better direction to head? Is one considerably less expensive than the other? Can I solder a piece of link into my existing cable, or will the heat be a problem for the "fusible" part? I checked Summit Racing so far, but they only carry up to 14g fusible link. IIRC, I used 4g for the alt cable.
 
info about fuse

Well at least we know what it does. Now u ask where to buy a fuse? Most stereo places have a fuse link up to 0 gauge. Circuit city might have these if I am correct. The fuses are real easy to replace also. It is a holder that looks like a barrel and both ends unscrew. They work great and are weather resistant. Now just have to find out which size fuse it is.?:confused:
 
The stereo places also have big circuit breakers you can buy if you don't want to use the fuses.

-Rob :)
 
OK, so it seems they are readily available. Not sure why I was having a problem finding them via google and summit racing :confused:.

I'll have to double check, but I think since my truck is a '98 it has the 135amp alt.

I'm going to look at the RPO codes in my glovebox (I have the code breakdown list at home for my truck) - I think one of the codes tells what size alt. Joe, did you keep your original alt when you put your Cummins in? If you did - and don't have an RPO cheat sheet - I can at least compare your code to mine for you.
 
A fusable link IS a fuse...
The difference is that a fusable link is a slow blow fuse - Very slow blow.
Normally a fuse is only there to protect the wire insulation. The only exception that I know of (there may be others) is to protect a battery. Batteries do VERY BAD things when hit with way too much current for very long (not too very long at that) time.
You got a plastic box filled with lead & sulphuric acid. It's very important to keep that stuff in the plastic box! DO NOT circumvent the battery protection scheme without doing the math!!!!!!!!!!!
 
DennisG01 said:
I think one of the codes tells what size alt. Joe, did you keep your original alt when you put your Cummins in?
Click to expand...

Yes I used the gm alt. From what I can see from advance auto it show I have a 100 amp but not saying that is right or wrong.

I think if you use a 100 fuse it should work fine so this way the fuse will go before the wire if I am correct.:thumbsup:
 
DennisG01 said:
Joe-

The RPO code for my truck is KW2 and that's listed as a 124amp alt. If you see KW2 in your glovebox, you got the same thing.
Click to expand...

Was in hurry n did not read this post.

I will check once it quits snowing. Thanks for the update..:thumbsup:
 
In searching around, I came across that "mega 175 fuse" term that Packratt mentioned. I figured "hey, this is the second time I've seen that term - let's see what this thing is", so I googled that term and it turns out it is a slow blow fuse (like fusible link) and is under $10. It can be purchased in many different amp ratings, also. Looks like it'll be a snap to install it, too. Unless someone advises differently, I believe I've found the winner! I'll have to see what I can buy these for when I get to my second job tonight.

But, one last question: Wouldn't I want a fuse equal to the output of the alternator?
 
Alternators are rated at some current for a few seconds - NOT continuous!
Fuses protect the WIRE INSULATION - NOT THE SOURCE!!
The fusible link in the charging circuit protects the battery and it's wire.

Please, do all the reading that you can on this subject before your truck goes up in a BLAZE of glory.... Fuses, fusible links, and circuit breakers are FIRE PROTECTION DEVICES. If you oversize fuses (etc) you are literaly playing with fire.
 
Well, I used the wrong word when I asked what amperage I should be looking for, but apparently this "Mega Fuse" is the newer version of fusible links. Radio, do you have a suggestion as to what size to use? What amperage is the stock fusible link? I called a dealer, but wasn't able to get someone that could help.
 
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