alternator upgrade issues
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"garage"=Natural Habitat
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From: Hamilton ohio
alternator upgrade issues
So i have been working on doing a taurus alt upgrade on my GSL-SE and I know electrical very well. I have used the search and followed every wiring diagram i can find and there are many. They all say the same things when it comes to wiring and thats how it is hooked up.
https://www.rx7club.com/attachments/...stall-copy-jpg
B+ from alt hooked directly to battery
A wire hooked to B+
S wire hooked to taurus alt stator spot and unchanged from factory
I wire hooked to Black wire / White stripe
now i also have my battery relocated to the storage bin all wiring was done with thick 2 gauge wire and has been grounded to bin frame and drivers side seat bolt.
My issue is this if i take a multimeter and go to the back of the alt i get 13.8 volts.
If i go to the battery while running i get 13.8 volts but my stock gauge says 11 volts. So I thought maybe the stock gauge was faulty but my battery keeps dying.
I have tried switching to the white wire on the alt no change tried re grounding no change.
Please help me figure this out I'm out of ideas.
https://www.rx7club.com/attachments/...stall-copy-jpg
B+ from alt hooked directly to battery
A wire hooked to B+
S wire hooked to taurus alt stator spot and unchanged from factory
I wire hooked to Black wire / White stripe
now i also have my battery relocated to the storage bin all wiring was done with thick 2 gauge wire and has been grounded to bin frame and drivers side seat bolt.
My issue is this if i take a multimeter and go to the back of the alt i get 13.8 volts.
If i go to the battery while running i get 13.8 volts but my stock gauge says 11 volts. So I thought maybe the stock gauge was faulty but my battery keeps dying.
I have tried switching to the white wire on the alt no change tried re grounding no change.
Please help me figure this out I'm out of ideas.
The GSL-SE is wired just like the S4 as shown here:

A Terminal: goes to Battery Positive terminal, NOT the Alternator output post
S Terminal: Loops back to Stator
I Terminal: goes to Ignition-switched 12v
What the diagram you used is doing is making the alternator behave like a one-wire one, which undermines its abilities by sensing voltage at the output post instead of at the battery. There is always a little bit of voltage drop between the two, and you want the alternator to see what the battery sees. Since your battery is relocated, the A Terminal should be connected to the main delivery cable, as close to the battery's positive terminal as realistically practical. My car has a dedicated 12v+ bus bar to facilitate this, which conveniently doubles as a jumpstart point.

A Terminal: goes to Battery Positive terminal, NOT the Alternator output post
S Terminal: Loops back to Stator
I Terminal: goes to Ignition-switched 12v
What the diagram you used is doing is making the alternator behave like a one-wire one, which undermines its abilities by sensing voltage at the output post instead of at the battery. There is always a little bit of voltage drop between the two, and you want the alternator to see what the battery sees. Since your battery is relocated, the A Terminal should be connected to the main delivery cable, as close to the battery's positive terminal as realistically practical. My car has a dedicated 12v+ bus bar to facilitate this, which conveniently doubles as a jumpstart point.
Thread Starter
"garage"=Natural Habitat
iTrader: (1)
Joined: Dec 2010
Posts: 133
Likes: 0
From: Hamilton ohio
The GSL-SE is wired just like the S4 as shown here:

A Terminal: goes to Battery Positive terminal, NOT the Alternator output post
S Terminal: Loops back to Stator
I Terminal: goes to Ignition-switched 12v
What the diagram you used is doing is making the alternator behave like a one-wire one, which undermines its abilities by sensing voltage at the output post instead of at the battery. There is always a little bit of voltage drop between the two, and you want the alternator to see what the battery sees. Since your battery is relocated, the A Terminal should be connected to the main delivery cable, as close to the battery's positive terminal as realistically practical. My car has a dedicated 12v+ bus bar to facilitate this, which conveniently doubles as a jumpstart point.

A Terminal: goes to Battery Positive terminal, NOT the Alternator output post
S Terminal: Loops back to Stator
I Terminal: goes to Ignition-switched 12v
What the diagram you used is doing is making the alternator behave like a one-wire one, which undermines its abilities by sensing voltage at the output post instead of at the battery. There is always a little bit of voltage drop between the two, and you want the alternator to see what the battery sees. Since your battery is relocated, the A Terminal should be connected to the main delivery cable, as close to the battery's positive terminal as realistically practical. My car has a dedicated 12v+ bus bar to facilitate this, which conveniently doubles as a jumpstart point.
Ok I understand thank you for clearing that up i will straighten that out tomorrow and let you all know how it goes. Thanks Akagis for the prompt and detailed response.
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