What is this on the positive terminal of my battery?

[Jerry Bransford]

2-pack 500 amp fuses and holders for $15. If 1 doesn't work wire them both in parallel.

https://www.amazon.com/dp/B07B53SYSX/?tag=wranglerorg-20

Adds one more point of potential failure in a circuit that could be required to work no matter what in a true emergency situation. I'll trust and go with what Warn recommends.

 

[Zorba]

Yes impedance does include simple resistance but when there's no Xc or Xl the Z (impedance) is nothing more than the DC resistance. Impedance is not a term that would be used in that 12 volt DC circuit. No big deal but...

No, no biggie - just the way I was "raised". A "low impedance" power source like a large battery as a for instance. But its all good! Sometimes I think the greatest impedance is the one between my ears - plenty of resistance, but lots of reactance as well!

 

[Zorba]

I have the response.

"Warn recommends wiring direct to the battery due to the high amp draw required to run them. Most of the winches will pull over 400 amps when under load and we have not found any fuse or circuit breaker that will reliably handle that."

Hmmmm. They may well be right regarding readily available DC circuit breakers - I couldn't find any that I was impressed with when I went looking. Fuses are another matter, there are fuses made that will handle hundreds of amps - even thousands. But OTOH, @Jerry Bransford is also correct, its emergency equipment that must not fail. So I made mine such that I can bypass the fuse and/or the solenoid if needed in a matter of a minute or two. I actually think the solenoid is more important than the fuse as it de-energizes the whole affair when its not actually in use - much like a starter. The 500 amp fuse - if it needs to blow, may take longer than one might like to do so, depending on circumstances. So it really boils down to what your priorities are, what your comfort level is, your experiences have been, etc, etc, blah, blah, blah...

 

[freedom_in_4low]

I have the response.

"Warn recommends wiring direct to the battery due to the high amp draw required to run them. Most of the winches will pull over 400 amps when under load and we have not found any fuse or circuit breaker that will reliably handle that."

2-pack 500 amp fuses and holders for $15. If 1 doesn't work wire them both in parallel.

https://www.amazon.com/dp/B07B53SYSX/?tag=wranglerorg-20

Doesn't seem like they looked very hard. 500A is not an uncommonly high electrical load in industrial equipment and they're quite reliable; otherwise technicians will complain nonstop about nuisance breaker trips or blown fuses.

That pretty much settles it for me, if that's all the reason they have not to do it. I have a 30' long, 10' tall rack of fuses ranging from 1 to 800A to choose from at work, at wholesale cost via payroll deduction.