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alternator wire


Datsun510Boy

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The output 'wire' should be more like a cable. 12 gauge at least, to prevent this from happening. I run mine directly to the starter lug for return to the battery positive side rather than trying to connect it to the molded battery cable. Buy a suitable lug and crimp it onto the end (I also soldered it) then wrap with that split harness covering all the new cars have and bolt to the starter.

 

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should i strip the wire and put a new piece on it or what ?

 

 

 

I would but do soem other cks. maybe that alternator is bad.

re ck the fuses.

 

if anything was done or added to make this happen you have to tell us we are not mind readers You u add a 5000mega watt amplifier on this

i cleaned fuse box put all new fuses none were blown or hot all my lights been brighter car been running great . did a few runs and the cable to alternator fell off looks burnt ill post a pic . oh and i cleaned the battery terminals put a new connector on the positive the other day 

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Make sure that the lug w/the burnt wire is not grounded inside the alternator.

 

 

 

he mean take a ohm meter ans test between that lug threaded post and the chasisi of the alternator hopefull it not shorted. I dont know the reading but if you get a number tell us. 50ohms is still a short.

 

 

to me look like the connected is old and correding away and the load go to much for it and just went bad. Im my opinion.

 

you would have to strip the end clean it up good and put a nice crimped (same syle round lug on there) and most cases will be fine)

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image1-4.jpeg

 

cleaned it up fixed the wire and connector .also my battery is ran all the way to the trunk so there was a connection in the middle that might have been hitting the frame i cleaned that up made sure its not touching frame or any metal good insulation tape and a cut water hose lol (gotta improvise ) it was already there i placed it wrapped around and in between the connection and any metal. now every thing is clean and hooked up alternator cord fine holding up for the few mile drives i took . Only problem is the Charge light stays ON . gonna take the battery to auto zone get it tested make sure its ok . also I'm going to test the alternator make sure its not blown . 

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Only problem is the Charge light stays ON . gonna take the battery to auto zone get it tested make sure its ok . also I'm going to test the alternator make sure its not blown .

 

Im sure your wire size is fine I run 35 and 50ampers with the same stock wire and run a H4 and H1 lamps but wired to starter lug of battery for the excess draw(short runs)

 

 

dont you have a volt/mutimeter?

 

Buy this works long before a Idoit light come ON

http://www.walmart.com/ip/Equus-Innova-3721-Battery-and-Charging-System-Monitor/15137663

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If running all the way to the trunk you need THICK cable for this. Twelve gauge at least. Run inside garden hose to armor it is good idea. Ground with same size wire and run forward to a transmission bolt so the starter is well grounded. Ground to body somewhere near the battery also.

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one can do like Datzenmike and upsize the wire and route it to the starter lug

I have 2 510 with trunk mounted batterys and both run the stock wht/red alt wire.. been just fine. Once running its fine.

Only startup I would worry about the batter cable size and of coase bigger is better. and isulated so it dont catch fire as it grounds out when you crash is even better

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My opinion, the recommendations for wire size are way too small, for both the starter, and alternator wiring.

 

Lets start with the starter.  (sorry)   It is an electric motor, more specifically an overloaded electric motor, that is why you should not run a starter more than 30 seconds continuously, without letting it cool down. 

An electric motor is designed to do a some specific amount of work, measured in watts, or kilowatts.  Watts is voltage multiplied by amps. 

If an electric motor cannot get full voltage, it compensates by drawing more amps.   It also turns slower.  A starter motor that gets more voltage, turns faster, and in in turn draws less amps.  

 

There is another issue going on.  The more amps you draw out of a car battery, the lower it's voltage goes.  This in turn, makes the voltage drop at the starter greater, and yes, there is a bit of a problem with too small battery cables causing the starter to pull the battery voltage more than it should.

 

Do not forget, lower battery voltage when cranking means lower battery voltage for the ignition circuit.

 

So to sum up, smaller battery cables to the starter work the starter harder, because it turns slower.  it also reduces the voltage available for the ignition circuit.   Bigger battery cables turn the starter and engine faster, and leaves a higher voltage available for ignition.  This means the engine starts easier, and sooner.

 

If the engine starts sooner, it draws the battery down less.  The alternator has less work to do to recharge the battery.

 

If the alternator wiring is too small, but sized "big enough" not to run too hot and melt insulation, there is still a voltage drop in the alternator to battery wiring.  The alternator actually put out a slightly higher voltage than the battery gets.  This is even more pronounced when headlights, or other accessories are on.   Datsun engineers put the voltage regulator close to the fuse box to compensate for this.  On internally regulated alternators, the alternator uses the "S" terminal to check system voltage away from the alternator.  Using a GM "one wire" alternator is a bad idea for this reason.

 

So, if you have too small wiring between the alternator, and the battery, the battery may not get full charge, or it will need a longer time to get fully charged.  This makes the battery voltage lower than normal and this effect is compounded with a remote battery location. 

 

And remember what I said about the starter wanting higher voltage?

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Whats the Best Way to check the Alternator ? whats I posted before?

 

use a volt meter and see what voltage is across the battery with no load on there. then rev it up and ck again . give us a reading at idle and say 2k rpms. then try it with the Lights on. Most time it will kill the voltage already.

 

If this is a external volt reg 510 then the volt reg maybe bad. Most time them youll get a overvolt indication on a volt meter but I notice I never have a Ignition light on when this happens.

 

you could always pull the alternator out and take to Napa to have them ck it out? if the above is too much beyond your IQ.

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One of the characteristics of the Datsun voltage regulator is that is charges slightly "too high" when the engine is first started.  the regulator is also temperature compensated.  Factory service manual says 15.5 volts is the upper limit for voltage, at freezing temperature.

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On internally regulated alternators, the alternator uses the "S" terminal to check system voltage away from the alternator.  Using a GM "one wire" alternator is a bad idea for this reason.

 

Sorry. Hope I'm not hijacking this thread, but can you explain further how the GM one-wire alt is a bad idea, and what's a better option when upgrading the old stock alts?

 

Thanks.

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The voltage at the alternator is not the same as the voltage at the load, because any wire has resistance.  The load could be a battery taking a charge, or headlights, or any number of electrical accessories.

 

A "one wire" setup uses the internal regulator of the alternator to check the alternator output voltage at the only place it has a connection, the alternator.

 

The "extra" wires measure the voltage remotely from the alternator, and the internal regulator of the alternator adjusts the voltage at the alternator to give you the correct voltage at that remote location, where the engineers who designed the electrical system decided would be a good place to use as a reference

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The output 'wire' should be more like a cable. 12 gauge at least, to prevent this from happening. I run mine directly to the starter lug for return to the battery positive side rather than trying to connect it to the molded battery cable. Buy a suitable lug and crimp it onto the end (I also soldered it) then wrap with that split harness covering all the new cars have and bolt to the starter.

 

12ga is way too small for a starter wire. 6ga or bigger is usually used and that's with the battery only a couple feet from the starter, nevermind in the trunk.  Should be 4ga or bigger, and then why wouldn't that be used as the charge wire too?

 

 

Absolutely right. I was mixed up with the alt. charge wire. Battery cable? Welding cable, big as you can afford.

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