# Alternator wiring

**URL:** <https://community.cartalk.com/t/alternator-wiring/168661>\
**Category:** Maintenance/Repairs\
**Tags:** suzuki, grandvitara\
**Created:** [August 14, 2020, 11:36am UTC](https://community.cartalk.com/t/alternator-wiring/168661 "2020-08-14T11:36:05Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![NG-34](https://avatars.discourse-cdn.com/v4/letter/n/eb8c5e/32.png) [@NG-34](https://community.cartalk.com/u/NG-34)\
**Post date:** [August 14, 2020, 11:36am UTC](https://community.cartalk.com/t/alternator-wiring/168661/1 "2020-08-14T11:36:05Z")

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[image|500x500](https://community.cartalk.com/uploads/short-url/qiMaPgv0OOFp7GKftq0k0zjr9Nr.jpeg)  
Anyone know how to wiring the alternator？My alternator type is with 2socket with “L”and “S”  
I have no idea about where the “S”go…can i just using a relay from battery to ignition switch to wire the “S” ？

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**Author:** ![COROLLAGUY1](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/corollaguy1/32/7575_2.png) [@COROLLAGUY1](https://community.cartalk.com/u/COROLLAGUY1)\
**Post date:** [August 14, 2020, 11:57am UTC](https://community.cartalk.com/t/alternator-wiring/168661/2 "2020-08-14T11:57:09Z")

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What year is your vitara?

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**Author:** ![NG-34](https://avatars.discourse-cdn.com/v4/letter/n/eb8c5e/32.png) [@NG-34](https://community.cartalk.com/u/NG-34)\
**Post date:** [August 14, 2020, 12:01pm UTC](https://community.cartalk.com/t/alternator-wiring/168661/3 "2020-08-14T12:01:02Z")

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i remember is year 1990…i will check it tommorow

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**Author:** ![NG-34](https://avatars.discourse-cdn.com/v4/letter/n/eb8c5e/32.png) [@NG-34](https://community.cartalk.com/u/NG-34)\
**Post date:** [August 14, 2020, 12:02pm UTC](https://community.cartalk.com/t/alternator-wiring/168661/4 "2020-08-14T12:02:48Z")

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![image](https://global.discourse-cdn.com/cartalk/original/3X/1/8/18596c0f4f1957b33b179155e6b49409f84af9da.jpeg)

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**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\
**Post date:** [August 14, 2020, 6:34pm UTC](https://community.cartalk.com/t/alternator-wiring/168661/5 "2020-08-14T18:34:45Z")

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It looks like you found the answer to your question.

The “S” lead is the battery sense lead the alternator uses to check the charge state of the battery. When the battery voltage goes down then the voltage regulator increases the alternator output to compenste for the drop. The “L” or lamp lead supplies power to the exciter circuit inside the alternator. It is important that the warning light works since it supplies current to the exciter through the lamp filament. If the lamp opens, the alternator will not be able to generate an output to the battery. Both leads are usually tied to power via the ignition switch power and a separate fuse.