# Can I make this alternator work for my '83 Rabbit GTI?



## Taytor (May 6, 2012)

I purchased this alternator in hopes that it could possibly be compatible with my Rabbit. 
If not, then I can use it on my Golf. 

Here are the backs of both alternators. The old one was the current alternator for the Rabbit. 
The new one is....well...the new one. 










Here are the plugs (and ground) that are on the rabbit. 










Is there a way to make the new alternator fit the Rabbit?


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## antichristonwheels (Jun 14, 2001)

both red wires to the big lug 

blue wire to the small lug 

ground to spade tab 
harness. 
That being said I have never seen this "replacement alternator" but I would not use it. I would get on rockauto.com and find a decent rebuilt original type. 

If you do use this I would run a new single fat red wire from the big lug to B+, a new blue wire and not hack the harness


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## Taytor (May 6, 2012)

There is also a recessed stud that says "B-" 

So in all there is a B+, B-, W, and a D+ 

So I can run a large wire from the b+ directly to the + battery terminal? 

What exactly is the purpose of the blue wire? 

And what is the purpose of the "w" stud? 

Thanks.


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## Taytor (May 6, 2012)

antichristonwheels said:


> both red wires to the big lug
> 
> blue wire to the small lug
> 
> ...


 So I did as you recommended, but I placed the ground on one of the bolts mounted on the body of the alternator. Will this be good enough? 

Should I move the ground to the "w" lug with the flat piece of metal? 

I ran the rabbit for a good while with a different battery. I place the battery in another vehicle, and it seems that the battery is perfectly fine. 

So that means that the wiring job works, right? 

Both of the red wires did get a little hot. Is this normal?


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## antichristonwheels (Jun 14, 2001)

So I did as you recommended, but I placed the ground on one of the bolts mounted on the body of the alternator. Will this be good enough? yes 

Should I move the ground to the "w" lug with the flat piece of metal? W is a pseudo tach output for diesels 

I ran the rabbit for a good while with a different battery. I place the battery in another vehicle, and it seems that the battery is perfectly fine. 

So that means that the wiring job works, right? hard to be sure 

Both of the red wires did get a little hot. Is this normal? This says it is working. This is why I said use a big fat single red wire


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## Taytor (May 6, 2012)

antichristonwheels said:


> So I did as you recommended, but I placed the ground on one of the bolts mounted on the body of the alternator. Will this be good enough? yes
> 
> hard to be sure
> 
> Both of the red wires did get a little hot. Is this normal? This says it is working. This is why I said use a big fat single red wire


 Yeah, as soon as I noticed that they were a little hot, I though about what you said. 
When I get back home later this week, I will run a thicker wire. 

When you said "hard to be sure" about the wiring being correct, about how long will it be obvious that something is wrong, IF something is wrong? 
If that "something" is wrong with the wiring, what could possibly happen? 

Thanks a lot for your answers.


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## antichristonwheels (Jun 14, 2001)

ITs hard to say just cause it runs a bit that all is good. Best thing is a real test: with the car off measure the battery voltage with a meter. Leave the meter attached and start it, leave it idling and put a load on it high beams and wipers should be plenty. When running the alternator should pick up and the battery voltage (now really alternator output voltage) should keep up at around 12.5-14Volts. 

Some cars the exciter wire and the alternator dont quite cut it and you have to rev it up to 2500 or so for the alternator to kick in. When this happen the voltage should jump from around 12 to around 14 and remain till you shut it off.


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## Taytor (May 6, 2012)

Heading to the auto parts store sometimes this weekend for a larger battery cable. 

Going to run a larger cable straigh from B+ to the positive battery terminal (as recommended above) 

Question: 

Why are there 2 red wires running to the battery instead of 1 large cable? 
Do both of them run to the battery? I dont want to cut open the harness to find out.


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## Glegor (Mar 31, 2008)

Taytor said:


> Heading to the auto parts store sometimes this weekend for a larger battery cable.
> 
> Going to run a larger cable straigh from B+ to the positive battery terminal (as recommended above)
> 
> ...


 because its hard to supply much over 30 amps thru a spade terminal.. so when you have more than 30 amps of current, the easiest thing to do, is use 2 spade terminals.. lmfao.. 

yes, rather than use a stud, and ring terminal, they used 2 spade terminals, and a plug assembly that OFTEN MELTED.. the 2 smaller wires are crimped on to one bigger wire about a foot into the harness.. there is only one single wire running to the battery from the alternator.. 

myself personally, i would run a single piece of 8gauge from B+ on the alt, to the positive side of the battery. also run a piece of 8gauge from the ground, to the body, or the battery as well.. 

i HATE the original charging wiring on older VW cars.. 

btw, the W terminal is usually used to drive the TACH on a diesel car..


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## Taytor (May 6, 2012)

Glegor said:


> because its hard to supply much over 30 amps thru a spade terminal.. so when you have more than 30 amps of current, the easiest thing to do, is use 2 spade terminals.. lmfao..
> 
> yes, rather than use a stud, and ring terminal, they used 2 spade terminals, and a plug assembly that OFTEN MELTED.. the 2 smaller wires are crimped on to one bigger wire about a foot into the harness.. there is only one single wire running to the battery from the alternator..
> 
> ...












Crappy picture, but I hope you can see the two red wires coming off of the b+ stud. 
I followed the 2 wires. They run deeper into the harness and dissapear off behind the engine compartment. 

There is currently a large cable running from the positive battery terminal clam to the starter (supposed to be there) and then the smaller red wire that also runs into the positive battery terminal clamp (only 1 red wire from the alternator? There is 2 coming off of the alternator, so where does the other one go?) 

I purchased a 4g cable from an auto-parts store. Should be PLENTY big lol. Im going to run that off of the b+ stud directly to the positive battery terminal.


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## LT1M21Stingray (Sep 14, 2006)

antichristonwheels said:


> Should I move the ground to the "w" lug with the flat piece of metal? W is a pseudo tach output for diesels



This.

"W" is for winding, straight AC volts, and is a tach output for diesels.


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## Taytor (May 6, 2012)

I picked up some battery cable (4g)

Ive been working out of town, so I havnt had a chance to run the cable yet.

Ill update as soon as any progress is made.



Thanks guys.


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