In Line Fuseable Link

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revbang1
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In Line Fuseable Link

Post by revbang1 »

I sent this out in a Personal Message, I think. Since I'm not sure, I'm sending this out to the whole group.

I am in the process of finishing an alternator swap using the Denso one wire. I received the alternator today. Dropped right in a non modified lower bracket on my 67 311. Looks like the pulleys line up great. I do need a shorter belt. Napa will have one tomorrow.

I do have 2 questions. When I explained to my local parts guy what I was doing,
1) he said that the fuseable link between the alternator and the battery would only protect the alternator. He said to protect the wiring harness I would need to put a link on before the fuse box (on the wire that comes from the starter I assume.) Is he wrong? Does that fuseable link protect the whole wiring system?
2) He also sold me a fuseable link that is basically a thinner wire that the ten gauge wire I am running from battery to alternator. He didn't have a regular 30 amp fuseable link that would bolt to the fire wall. Does it matter what kind of fuseable link I use?

Thanks in advance for the help. I am close to having my 67 on the road for the first time in 10 years! Mark
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notoptoy
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Re: In Line Fuseable Link

Post by notoptoy »

The main reason to have the fusible link is for the heavy white wire, because it goes to the ammeter, the ammeter will burn up as a very expensive fuseable link if you don't have a fused connection to go first. This indeed protects the wiring in the car as it goes from ammeter to the rest of the system.
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fj20spl311
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Re: In Line Fuseable Link

Post by fj20spl311 »

Your auto parts guy knows his stuff.
You need protection on the wiring from the battery. That's usually a fusible link in the small pigtail wiring that goes between the battery cable at the starter and the wiring system white wire. Without that protection the system can meltdown if the system is shorted before the fuse box.
This has nothing to do with your alternator installation. Ture for All Cars.

You need protection from the Alternator passing too much current through the Amp meter. The easiest solution is to run a 10 gauge wire directly to the Battery or starter cable. You may want to install a circuit breaker or fusible link in the circuit, but should be 65-100 amps. The problem with this solution is the Amp Meter will no longer show when you are charging.

If you want the Amp Meter to still function, it becomes a more difficult problem. The amp meter range needs to changed by changing or adding a "shunt" across the amp meter. I have yet to find a shunt for this purpose. I suspect that if you had a spare Amp meter or buy a cheap aftermarket 50 amp meter you could get one from the amp meter and use the shunt on your meter.....This is something that maybe Jon Frampton could answer.

My solution for my 67.5 was to have Jon change my Amp meter to a Volt meter.
volt meter.jpg
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Re: In Line Fuseable Link

Post by Nissanman »

There are a variety of devices that you can use to protect the car wiring from current overload: -
Image

Metal can circuit breaker

Image

Maxi Fuse weather proof holder

Image
Image

Old school glass fuse and holder


081120151864.jpg



I used the metal can breaker mounted under the ground screw of the alternator.
Then I ran a short 30A wire from the alternator output terminal to one side of the breaker, the other side has the 30A white wire to the external Voltage Regulator.
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Habitat.pat
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Re: In Line Fuseable Link

Post by Habitat.pat »

67.5’s are easier to convert either to a voltmeter or higher current ammeter than other years. It turns out that the ammeters & voltmeters from a 240z through 280z can be swapped in easily. I swapped in a 60 amp unit about 15 years ago & have a voltmeter on the shelf to go that route when I rework my harness.

All that was needed was the ammeter & a piece of 1/4” pvc to mount the gauge into the housing. Worked great.

Too bad the z car parts are getting so hard to find.

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Pat
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Re: In Line Fuseable Link

Post by Nissanman »

Just a little point I wish to raise. Some folks are under the impression that the Ammeter measures the TOTAL current draw of the Alternator. That is not so, in the normal wiring situation. The Ammeter is there to indicate the state of Charge/Discharge with respect to the storage battery. As a driver you really have no idea, nor do you care, how much the alternator is outputting to run all the electrics during normal operation. What the Ammeter indicates is how well the storage battery is taking a charge and how well it will perform the next time you demand that it provides hundreds of amps to crank the engine. So, for example, if you upgrade the alternator to a higher output device with modern reliability, you really have not affected anything with regards to battery maintenance. But you MIGHT have planted a bomb for your OEM electrical wiring if you don't protect it in a suitable manner.
Just my take on the situation.
Nissanman, just trying to help.
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Re: In Line Fuseable Link

Post by redroadster »

With the new alternator, a amp meter is not really needed like it , is a good idea with the old style.
Because of the redirect current windings design , back then called a Square Wave alt.
( a auto electric rebuilder came up with a way to almost double alt output , by. only bending the winding coil)
and internal SS reg. The later type can hold /keep up with high current demands , which was not the case on those stock Roadster alts
A volt meter is all you need, a multtimeter close at hand if you want to know amp draw
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Re: In Line Fuseable Link

Post by caraddict »

Habitat.pat wrote: Thu Jun 07, 2018 11:09 pm 67.5’s are easier to convert either to a voltmeter or higher current ammeter than other years. It turns out that the ammeters & voltmeters from a 240z through 280z can be swapped in easily. I swapped in a 60 amp unit about 15 years ago & have a voltmeter on the shelf to go that route when I rework my harness.

All that was needed was the ammeter & a piece of 1/4” pvc to mount the gauge into the housing. Worked great.

Too bad the z car parts are getting so hard to find.

Peace,
Pat
We have converted every year roadster ammeter to volts and they all pretty much take the same amount of work. These are for RCMikes beautiful new creation which explains the 10K tach and the 160 speedo. Can't wait to see this car on the road!

ImageRCMikesGauges by Jon Frampton, on Flickr
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