Fuse for alternator charge wire??

[HTElectrical]

What is everyone using to protect the charge wire from the Alt. to the Starter?  Fuse, Fusible link?  What size wire, and Alt. Rating?

Thanks in advance.

 

[John@Outfront]

clearly the fuse must be rated above the alternator output, that is why most buggies don't protect that circuit as you need to have a 100+amp fuse.  we don't protect that circuit but we like to make our charge cables out of #6 gauge welding wire.  good stuff and flexible.  i buy mine from mcFadendale hardware and they have all the copper ends and you can buy it by the foot.  we only buy black, do a small band of red shrink with some clear over that

 

[Rockwood]

Always used something like this guy:

https://a.co/d/9fNInKS

Makes working near it a snap as well: super easy to safe. 

 

[Kraut_n_Rice]

Most OEMs don't protect the cable from the alternator to the battery/fuse box.  Occasionally they will put an undersized fusible link.

Unnecessary IMO, but if you're gonna do it, pick something a good percentage higher than your alternator's output.  

I was building a project that needed to have a certification done by Cummins since we were the OEM of the equipment.  Warranty n'chit..  They required a fuse between the alternator and positive battery buss.  IIRC, the alternator is 125A and the fuse is at least 200A, maybe 250A.  Side note on the Cummins industrial practice being extreme.. we couldn't "chassis" ground anything to do with the engine.  It all had to be bussed to the battery.  We even had to ground the starter, which is bare bolted to the block, then ground the block.  All of which is done in 4ga cable...by recommendation. I also had to install an intake heater grid circuit that would only turn on below 0*F, even though our sh!t will NEVER be run below 40*F...

Circuit breakers like Rockwood noted above are nice because they are resettable, but the are big and can be contaminated with sand and dust.  IF I were going to protect my charge wire it would be with a fuse holder like this, then pick your fuse amperage and buy a couple spares..  FFIW...Waytek is a great source for electrical goods...

TLDR...don't need it.

 

[r3meyer]

Kinda pointless unless its a very long run, then I would use a blue sea terminal fuse.  The fuse is in the connector.

 

[Chingon619]

I had a very nice fusible link that I re-used from my vette harness until the day I started smelling something toasty. Looked back as I was connecting the battery, and seen smoke. Went to investigate and the link had fried. Thought, that's weird. Went to button up the battery only to find I had my terminals connected backwards. Uhh durrrr. So now running a 10g (guess) wire but no fuse and worried for a while. I should fuse it again though.

 

[John@Outfront]

Kinda pointless unless its a very long run, then I would use a blue sea terminal fuse.  The fuse is in the connector.

i agree, on a Subaru the wire is only 2' long, not long enough to worry about a short on the wire.  and a short in the alternator to ground is very rare 

 

[HTElectrical]

Circuit breakers like Rockwood noted above are nice because they are resettable, but the are big and can be contaminated with sand and dust.  IF I were going to protect my charge wire it would be with a fuse holder like this, then pick your fuse amperage and buy a couple spares..  FFIW...Waytek is a great source for electrical goods...

That is what I used with a 100A fuse.  It looks like one side might of loosened up and overheated causing the fuse and holder to fail.

After looking up the holder I used it appears to have a nylock nut on it so I doubt that it loosened up.