The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain > LSx Swaps

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-28-2019, 03:32 PM   #1
cebra
Registered User
 
Join Date: Jan 2018
Location: Durham, North Carolina
Posts: 782
Alternator/Volt Reg Wiring with LS Harness

Can I eliminate all of these wires (2 reds to alt/volt reg, 2 grounds, 1 white, 1 blue, 1 brown)....the brown wire (which I may not have as I have 5 gauge panel) and then pitch the voltage regulator or do I need any of these on my standalone harness?

From what I can tell my LS standalone harness feeds from a power wire off the starter and has an alternator plug on it so I wouldn't know where I would need to splice any of these wires into the standalone harness? Trying to finish off a few things before my swap gets started. Thanks.
Attached Images
 
__________________
My Daily Driver Build: http://67-72chevytrucks.com/vboard/s...d.php?t=755668
cebra is offline   Reply With Quote
Old 03-28-2019, 03:55 PM   #2
mongocanfly
Post Whore

 
mongocanfly's Avatar
 
Join Date: May 2015
Location: Alabama
Posts: 14,658
Re: Alternator/Volt Reg Wiring with LS Harness

I dont remember exactly how I did it but none of the old alt. wires are needed and I terminated them...the LS harness has it's own alt plug...and the power wire from alt hooks back into the hot side of the system...
I have a volt gauge so it's just reading system voltage..
__________________
Mongo...aka Greg

RIP Dad
RIP Jesse

1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598
Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334
Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563
2023 Chevy Z71..daily driver
mongocanfly is offline   Reply With Quote
Old 03-28-2019, 04:02 PM   #3
cebra
Registered User
 
Join Date: Jan 2018
Location: Durham, North Carolina
Posts: 782
Re: Alternator/Volt Reg Wiring with LS Harness

Quote:
Originally Posted by mongocanfly View Post
I dont remember exactly how I did it but none of the old alt. wires are needed and I terminated them...the LS harness has it's own alt plug...and the power wire from alt hooks back into the hot side of the system...
I have a volt gauge so it's just reading system voltage..
I thought I could remove it all but wanted to make sure, I have a sunpro style volt gauge just feeding off a switched 12v wire so I think I can get rid of it all with the standalone harness.
__________________
My Daily Driver Build: http://67-72chevytrucks.com/vboard/s...d.php?t=755668
cebra is offline   Reply With Quote
Old 03-28-2019, 11:59 PM   #4
Wildkarde
Registered User
 
Join Date: Mar 2018
Location: Ardmore
Posts: 100
Re: Alternator/Volt Reg Wiring with LS Harness

What exactly is the alternator out of, it makes a difference is exactly how to wire them. You do need at least one of the wires in the small plug to get the alternator to charge. But it can't just be wired to 12v or the alternator will burn itself up.
Wildkarde is offline   Reply With Quote
Old 03-29-2019, 07:47 AM   #5
cebra
Registered User
 
Join Date: Jan 2018
Location: Durham, North Carolina
Posts: 782
Re: Alternator/Volt Reg Wiring with LS Harness

Quote:
Originally Posted by Wildkarde View Post
What exactly is the alternator out of, it makes a difference is exactly how to wire them. You do need at least one of the wires in the small plug to get the alternator to charge. But it can't just be wired to 12v or the alternator will burn itself up.
2000 4.8L Tahoe, it has 4 wires to it on the standalone harness.
__________________
My Daily Driver Build: http://67-72chevytrucks.com/vboard/s...d.php?t=755668
cebra is offline   Reply With Quote
Old 03-29-2019, 12:36 PM   #6
mongocanfly
Post Whore

 
mongocanfly's Avatar
 
Join Date: May 2015
Location: Alabama
Posts: 14,658
Re: Alternator/Volt Reg Wiring with LS Harness

The alt plug is contained in the LS harness and is controlled thru the ecm...the power supply side of the alt just goes back to the 12v side of the elec system....no need for any other wiring....
__________________
Mongo...aka Greg

RIP Dad
RIP Jesse

1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598
Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334
Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563
2023 Chevy Z71..daily driver
mongocanfly is offline   Reply With Quote
Old 03-30-2019, 02:21 AM   #7
Wildkarde
Registered User
 
Join Date: Mar 2018
Location: Ardmore
Posts: 100
Re: Alternator/Volt Reg Wiring with LS Harness

Is this a harness you are building, or one you've already bought? You can wire these alternators 2 ways, either through the computer for charge control, or just letting it charge all the time.

If going the computer route, the L terminal(pin B on the connector) goes to pin 15 on the red ecm connecto and the F terminal (pin C) goes to pin 52 on the red connector. Wired this way the ECM will control the alternators charging voltage.

If you dont want to go that route you can connect the S terminal(pin D) to switched 12V, and the L terminal(pin B) to switched 12v through a 470 ohm resistor. Not using the resistor will result in alternator damage. This setup will have the alternator charging at ~14V all the time.

The unused wires on the 4 pin alternator connector can be discarded.
Wildkarde is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:13 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com