Need Help with LS Swap Alternator Wiring!

Technical Discussions
1

I’m currently in the middle of an LS engine swap and I’ve hit a bit of a snag when it comes to wiring the alternator. I want to make sure everything is connected properly, but I’m struggling to find a clear guide on what wires go where.

Here’s what I need help with:

  • Wiring Diagrams: Are there any detailed diagrams available that show how to connect the LS alternator?
  • Tips & Tricks: Any suggestions for common issues to watch out for while wiring?
  • Parts Recommendations: What specific connectors or wiring kits have you used that worked well?

I want to ensure that everything is set up correctly for optimal performance. Any advice or resources would be greatly appreciated! Thanks in advance for your help.

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2

I’m starting an LS swap too! For the alternator, make sure you know if you’re using a stand-alone harness or integrating it with the existing wiring. It can get tricky!

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3

That’s a good point! If you’re integrating, don’t forget to check the harness wiring colors to avoid any confusion down the line.

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4

If you are going with a stand-alone harness, be sure to wire the alternator properly. It usually needs a signal wire connected for the PCM to manage the charging.

5

Exactly! The alternator’s battery voltage sense wire is crucial, or your system could act wonky.

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Don’t forget to consider the amp rating too! An LS swap often requires more power than the stock alternator can provide, especially if you have aftermarket accessories.

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For a lively LS swap, I went with a 150A alternator! It’s been fantastic. Just make sure your wiring can handle the increased load!

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Good point! Anyone else had issues with the stock wiring not keeping up during heavy load?

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I had to upgrade my wiring completely! The factory stuff wasn’t cutting it. Make sure to use a good gauge wire for the alternator connections.

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Absolutely! And make sure to use proper grounds—neglecting that can lead to all sorts of electrical gremlins!

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Haha, electrical gremlins sound like a band! Seriously though, I laughed but it’s true. I’ve had weird issues because I overlooked ground connections before.

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12

I had a similar issue with my LS swap alternator wiring. Check if you have the right connections; it’s easy to mix up the battery and field wire! Sometimes, grounding issues can cause weird electrical behavior too.

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13

Exactly! I made that mistake once. Also, ensure your connections are clean and tight; corrosion can lead to poor performance.

14

Don’t forget about the voltage regulator! If it’s not wired correctly, it can prevent the alternator from charging properly. Mine was wired wrong at first and caused a lot of headaches.

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Good point! I had to troubleshoot my voltage regulator too. Sometimes, it’s just a faulty part that doesn’t get enough attention.

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16

Also, consider the alternator’s ground. I had a friend who was chasing electrical issues for weeks before realizing the ground connection was loose. Sometimes it’s the simplest things that throw you off!

17

So true! I spent days fixing my wiring harness when a bad ground was the culprit all along. It’s so frustrating!

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Is anyone using a different alternator than stock for their LS swap? I’ve heard some aftermarket ones require different wiring setups, which can be confusing. Just a thought!

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Yes! I switched to a higher amp alternator for better output, and I had to completely change my wiring. Make sure you do your research on any modifications!

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If you’re still having trouble, consider posting a wiring diagram. Sometimes a fresh set of eyes can catch something you might have missed. I love the LS swap community for that!