Looking at the MAD elec mod where I wanna run a 10g wire from the alt batt terminal to the start relay. What's the difference between using a fusible link rather than a glass fuse in one of the inline plastic connectors?

A glass fuse will blow fast. The link functions as a slow-blow fuse to allow for momentary current flow that is technically beyond the limits of the 10 GA wire, but OK due to short timespan.

you want the link.

Do I understand your plan (MAD?) correctly, you want to fuse the output of the alternator, it s rated amperage is, and if so, why?

http://www.delcity.net/store/Maxi-Fuse-Holders/p_11183

Thanks for the replies. Just wanted to ensure some sort of protection device is in place, I understand difference now. So, I can essentially make my own fusible link by splicing in a smaller gauge wire? Ive read two gauge sizes smaller, but how long is it to be? 2 inches?

He is referring to the Mad Electrical upgrade found in this link.
http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Basically it amounts to running a large wire from the alternator output stud directly to the starter relay. You are bypassing the bulkhead connector and charging the battery in a more direct fashion.

To the OP, are you planning on keeping the stock alternator wire hooked up or are you going to remove it? If you are leaving the stock wire in place, I think it would be OK to run a fuse. If the fuse blows, you still have the original wire there as a backup.

I haven't decided what I want to do yet as far as protecting that jumper wire on my car. Technically, you could have a short in the center of the wire. 1 link or fuse at the end of the wire won't cut power to that wire.(power will still be fed from the other end) I think I want to run a link/fuse on each end. That way if there is a short, both will blow and the jumper wire will be completely dead.

I'll also add a fusible link to the existing output wire right off the alternator. With a jumper wire in place, you are now feeding the interior with two wires.(original charge wire is now feeding interior as well)The one side already has a fusible link. With a link added right off the alternator, both wires are protected from an interior short.(both links should blow and cut all power to the interior) Basically I'll be doing what the MAD article says except I'm leaving the original wire hooked up to the alternator instead of connecting it to the starter relay.

The Glass Fuses, and ANL/MIDI/Maxi/fuseable link are different in function and rating.
The glass fuses open quickly (less than a second) at their rated capacity, so a current spike will take one out easy. The ANL/MIDI fuses are slow to open. I think the spec for 100% current rating an room temp is around 100-Hours for the fuse to blow? These are usually sized to they blow when the current is around 150%-200% the rated current, and it may still take a minute at the rating to blow.

Usually a fast acting glass fuse is used to protect an electronic component part of hardware like the radio, and the ANL/MIDI/Maxi/fuseable are used to protect the wiring from melting in short circuit conditions.

Most cars use the glass and little fuse, fast acting fuses, to protect the hardware and wiring. I think this is mostly because of the lower cost and smaller size of those fuses.

The smaller mini-ANL fuses are popular for wiring stereo equipment, and are available in many current ranges, so they make a good replacement for fuseable links, and fuses for most car stuff like cooling fans and fuel pumps that have a high in-rush (initial) current spike.

I understand now what the plan is, but unclear "why" the OP needs a fused alternator feed, most cars of our era never had one, intentionally, the bulkhead solution/bypass is certainly advised, but the fuse, I don't know. Francis wiring? had a graphic posting on the downsides of fusible links, that would most think twice about the benefits.

Here is the article I believe you are referring to.

http://www.dragzine.com/tech-stories/ign...francis-wiring/

On the fusible link and its material... The fusible link is generally 2 gauge sizes smaller than the charge wire. It is not a standard copper wire however. It is a specific material that will melt and open with sustained overload. Fusible link wire is available at AP stores up to around 14 gauge. Auto electric stores carry heavier gauges.

A short length of copper wire would carry a heavy overload a long time before failing and provide no protection.

FWIW I run 10 gauge fusible link on my 6 gauge charge wire. No issues with this setup.

They had the alt output fused by a fuseable link. It was usually at the starter relay because the alt output wire on a stock setup on our older Mopars goes back to the ammeter and through the ammeter back to the starter relay through the fuseable link. If the alt or the alt out wire shorts it will blow out the fuseable link at the starter relay. The output wire is not a dedicated wire with the stock wiring.
Course when you run a dedicated output wire the ammeter wont show a charge. Ron

as said definitely not a glass fuse. the Madd bypass is used but will render the ammeter inaccurate. seperate issues. I have not done it but I dont see a problem with a piece of 14 ga FL at the alt for the bypass EDIT (for your 10 ga bypass). In my exp fusible links open too late. way back on here an electronics guy posted an electronic fuse or circuit breaker that sounded like a good option. there's gotta be a better way to protect the circuit. on my old '66 the wiring insulation melted/shriveled & the fl did NOT open