Alternator shorting out ?

[solrac]

Thanks jdinner and digibeam . Just wanted to make sure I wasn't crazy lol

[jdinner]

That's what he already said Robert. It is going to the battery but it is attached at the starter positive terminal with battery cable....same thing.

[Robert]

I am having issues with my electrical system. One bad hung was the wiring that was went to me.
But also I think my alternator is has a short.
Has any one heard of the alternator battery stud have negative current going tru it ?
If I use my test light from battery to the b+ alternator stud my test light lights up.

The large
 stud should go to the battery, for charging!

[jdinner]

I do have the stock ls4 alternator. It shorts out fuse box when  I connect the b+ terminal to battery wire. The way fieroking made me the harness is a big red wire from alternator to starter then to battery. On the battery connector there is also another big red wire that goes to fuse box. So when it is all connected together besides to battery it shows some of the fuses to have ground current.

I belive that I do have a one wire exciter. I have the one big wire that goes to starter then battery. And on the pigtail of the alternator there is only one wire. I am not quite sure what it connects to tho. 

The one wire from the pigtail should be connected to a light bulb in the dash. The circuit will look like this;
Fuse panel 12V+ Ignition ----> bulb ----> alternator.

Are you saying you have a testlight lighting up some of the fuses when the alternator is connected and battery is not in the system?
Yes? That's normal.
Connect the battery to the system and this condition will disappear. Items in the fuse panel that are connected to motors, bulbs or other loads will always appear to be going to ground when tested like that.
The wiring you described from Fieroking sounds correct.

[solrac]

I do have the stock ls4 alternator. It shorts out fuse box when  I connect the b+ terminal to battery wire. The way fieroking made me the harness is a big red wire from alternator to starter then to battery. On the battery connector there is also another big red wire that goes to fuse box. So when it is all connected together besides to battery it shows some of the fuses to have ground current.

I belive that I do have a one wire exciter. I have the one big wire that goes to starter then battery. And on the pigtail of the alternator there is only one wire. I am not quite sure what it connects to tho. 

[jdinner]

solrac, what kind of vehicle is that alternator in? Is it on an LS4 engine?
What I see is that that alternator has circuits that are controlled by the Powertrain Control Module and Body Control Module. A signal is sent to the alternator and feedback is sent back to both computers.
If you are building a replica and plan on using that alternator I suggest you take it to an alternator rebuild shop and have them modify it to work with a single exciter wire through a dash light bulb and the battery terminal.

The battery terminal does not go to the fuse panel.

[Digibeam]

how was the alternator shorting out your fuse box if it wasn't connected to anything?

[solrac]

It is a denso. Part number. 15139480
The thing was that it was shorting out my fuse box.

[jdinner]

What you are seeing with the test light is normal. Not to worry. However, 12.75 volts (not amps) is very low unless they were loading it up to maximum amperage. A typical amperage rating during a test should be around 60 to 150 amps. It all depends on the type of alternator you have.
A running voltage with minimal load on it should be 14.2 volts. A good voltage will be anywhere from 13 volts to 15 volts.

To answer your question, "alternator shorting out?" .. NO.

What make and model alternator do you have?

[solrac]

The alternator wasn't connected to anything yet. Just bolted on the bracket. If I unbolt it negative current doesn't show up. Only when it is bolted it shoes negative current flowing on the b+ stud.

I took it to autozone to get it tested and it showed 12.75 amps.
But failed one test. It showed 11.90 amps. They do 3 test and showed different amps on each on of them.

[Digibeam]

what side of the battery are you connecting to?  and also what is your voltage from the alternator when it is turning?  ( if any)
my immediate thoughts are the diode pack or the regulator is hooped.
but without specific info it is very hard to diagnose..
perhaps an explanation of your electrical issues?

[solrac]

I am having issues with my electrical system. One bad hung was the wiring that was went to me.
But also I think my alternator is has a short.
Has any one heard of the alternator battery stud have negative current going tru it ?
If I use my test light from battery to the b+ alternator stud my test light lights up.