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Old 03-25-2018, 12:48 AM   #1
lux
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When to upgrade to high amp alternator?

I just put in a LED headlights upgrade and now I think I have voltage problems.
My RideTech display gave a low voltage warning and my power amp was dropping out.

Its an LS1 swap with;
2 air compressors, RideTech system
1 small power amp
1 small powered sub
Vintage air

I'm guessing I need to upgrade but, how many amps on new alternator?
Is there an advantage to a 1 wire alternator? Or just stay factory wiring?
Whats a good alternator brand?
Should I also upgrade the wiring size?
Any other suggestions?

Thanks
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Old 03-25-2018, 09:07 AM   #2
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Re: When to upgrade to high amp alternator?

Lux-
It sounds like you need to do some forum searches. There are some great threads on this forum that will answer your questions.

Having said that, we need to know what you currently have for an alternator. Do you know what capacity the one you have is?

Personally, I'd say it never hurts to upgrade, as it sounds like you've got some high-draw items that could benefit from the added capacity. I just upgraded from a 36amp (?) to a 94amp alternator.

Here is the thread on the wiring discussion we had:

http://67-72chevytrucks.com/vboard/s...d.php?t=757426

Also, lots of good reading in this FAQ article:

http://67-72chevytrucks.com/vboard/s...d.php?t=119379

I'm not sure how much advantage there is to a 1-wire upgrade, but the upgrade to an internally regulated unit seems to be worth it.
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Old 03-25-2018, 10:56 AM   #3
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Re: When to upgrade to high amp alternator?

Thanks Saxart,
The alternator on my LS1 is stock and puts out 105 amps.
Thanks for the thread links, I'll read them.
I also read that my sound system amplifiers could benefit from a capacitor, does anyone know about this? I'll do a search on the site as well.
I'm thinking I'll upgrade, I'd love suggestions on brands of alternators to look at?
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Old 03-25-2018, 02:56 PM   #4
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Re: When to upgrade to high amp alternator?

Take your pick.

https://www.amazon.com/s/ref=nb_sb_n...ternator&ajr=0


A CS 144 would probably be enough, but the AD 244 will power the neighborhood. You will have to upgrade your wiring if you haven't already and use a separate junction.

The AD 244 will be a larger in circumference but it will bolt in place.

If you can put an amp meter in series with the negative battery cable and the post, then turn on the key and one by one turn on the loads with the engine off. Add up the amps each draws and that will tell you what your total draw is then figure 50% of that and that should be the size of the alternator you need.

For your fans and air you can take the fuse size and reduce it by 20% for the draw. Most fans will draw about 15 amps and the air will be slightly less. It should be labeled on the compressor or the instructions for vintage air.

I'll post a link that tells the size of the alternator depending on the loads if I can find it.
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Old 03-25-2018, 03:06 PM   #5
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Re: When to upgrade to high amp alternator?

Look at this.

http://www.onallcylinders.com/2015/0...ut-alternator/
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Old 03-25-2018, 03:19 PM   #6
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Re: When to upgrade to high amp alternator?

Thanks VetteVet, thats good reading for me.
Can I just use an amp clamp around the positive lead at the battery?
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Old 03-25-2018, 03:23 PM   #7
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Re: When to upgrade to high amp alternator?

Typically LED lights draw far less energy that comparable incandescent or halogen bulbs. I wouldn't guess the LEDs were source of voltage drop in and of themselves. My recommendation is to use a DVM to test voltage drop at the headlight connectors or other power terminals that you may be drawing excessively on your system. Also test the alternator directly.
My 2¢....

Dan
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Old 03-25-2018, 03:27 PM   #8
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Re: When to upgrade to high amp alternator?

PS, are running a capacitor between your amp and power lead? The pull that a decent can put on your charging system can be significant. A "cap" stores that energy for the amp to pull from rather than overly taxing your alternator. I have a 1200w amp in my 06 Sierra and a 3.5 farad cap ahead of the amp. Even when I push the amp my headlights don't and dash lights don't dim with the bass hits. I hope I'm being helpful.

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Old 03-25-2018, 06:34 PM   #9
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Re: When to upgrade to high amp alternator?

Thanks Dan,
I thought the same about LEDs, thats why I went with them over halogen.
I am considering a capacitor for my power amp and powered sub.
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Old 03-25-2018, 09:31 PM   #10
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Re: When to upgrade to high amp alternator?

Quote:
Originally Posted by lux View Post
Thanks VetteVet, thats good reading for me.
Can I just use an amp clamp around the positive lead at the battery?
sure it should work on either lead but the positive might read better.
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