Where Do The Fusible Links Go?

Hello all,

ive been tackling some wiring upgrades and useless removals along the way in my project. I haven’t placed any fusible like in anywhere and I wonder if anyone can tell me where the main ones need to be placed and sizes?

I’ve seen some specific diagrams without them and done with. I want to be safe so any help would be great.
Thanks!

 

I have a Factory 66 wire harness in my Jeep, and there are no Fusible Links in it. Anything I added I just put inline fuses in like the factory did, Radio and electric wipers. I did put a 110 amp 10SI one wire alternator in it, probably should put a fusible link in it, but don't know where and why? So I am watching your post too. Good Luck

 

my jeep doesn't have any . now my old ranger pick up . the fusible link saved it from burning down in work parking lot
when the alternator shorted out . fusible link is at positive side(+) of starter solenoid to large terminal of alternator

 

No fusible links prior to 1975 (?) in a CJ, AFAIK.

Ammeter or none?

They are placed to protect the Jeep from the stored energy in the battery. Placed between the battery and the alternator and between the battery and the Jeep.

 

Yeah none of my wiring is stock. It has all been done and Jerry rigged over the years this why I want to make it right. I’ve just seen diagrams with, without and inconsistencies so was hoping to find info.

so are you saying a fusible link would be on this large positive wires? I’ve retired the positives to a common post so not sure if that would make a difference or not.

 

I'll reference the ford again
fusible link 10ga 60A at starter solenoid . from there it goes to a terminal post . where it splits 3 ways . one wire to alt . two to inside of truck

 

If you follow the Jeep wiring, there are two "early" configurations with fusible links.

The '76ish Wagoneer has an ammeter and one fusible link. When charging, current goes from the alternator, to and through the firewall. At the dash, there is a splice that feeds all the Jeep stuff like lights and ignition. Current then goes through the ammeter, back to the firewall and connects to the battery at the starter solenoid using a 14ga fusible link. No protection on the starter cable.

The '75-up CJ has a voltmeter and two fusible links. From the alternator, there is a 10ga wire that connects directly to the starter solenoid and the battery via a 14ga fusible link. The dash connects to the starter solenoid and battery through another 10ga wire and 14ga fusible link. No protection on the starter cable.

In each case, the fusible link is protecting the Jeep from fire by preventing a direct short to the battery. Such a short can sink massive current, and the weakest link will burn up instantly. The fusible link is designed to be the weakest link and be fireproof, so it won't set the surrounding whatever on fire when it fuses. In Ron's Ford case, they placed the fusible link further back, maybe as part of the battery cable? Not sure from his post whether it protects the starter cable or not... same idea though.

 

orange wire connected to blue wire is fusible link . hope this helps

 

I hate fusible links. Replacing one is a hassle. I suggest a slow blow style fuse instead. You can get them in maxi blade, PAL, inline, etc.....
They are simple to replace and don't require cutting, crimping, or soldering.

 

I've only messed with one, adding a 14ga fusible link from Bussmann to my J20 when I replaced the ammeter with a voltmeter. Very easy.
https://www.amazon.com/gp/product/B001BXR9L8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

How often do you short out the battery and need to stop the Jeep from burning to the ground? Cheap, effective, dead reliable insurance.

 

So is that going to the Alt?

 

as I said before . fusible wire from solenoid . goes to a terminal block (single stud) . from there one wire goes back to alternator . two go to I would guess fuse panel . so there would be 4 wires on terminal block

now lets get back to my jeep . No fusible links . one 10ga wire from starter solenoid . battery side . to back of alternator . jeep picks it power for everything at large post on solenoid . another 10ga wire to light switch . off of that terminal power is split in every direction . now take note . the breaker on light switch is for only the lights . not the rest of jeep . I have inline fuses on every circuit

 

From the starter solenoid -
Starter cable.
10ga wire to alternator that charges the battery - this should IMO have a 14ga fusible link at the solenoid end.
10ga wire to the lights, that powers everything else in the Jeep except the starter motor - this should IMO have a 14ga fusible link at the solenoid end.

This is the same way that a 1975 or newer CJ-5 is wired. Two fusible links, one melts if there is a dead short in the alternator, the other melts if there is a dead short anywhere else except the starter motor.

When I say "dead short" I mean a short somewhere that is otherwise unprotected by a fuse or breaker in the harness.

 

Thank you. I am using a main single terminal positive post so i assume i would need on both sides of the post? Since there really isnt a direct cable.

 

I don't know what that means.