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 06-30-2015, 10:29 AM   #1
Big Port Jimmy 6
Addicted to Rust
 
Big Port Jimmy 6's Avatar
 
Join Date: Dec 2009
Location: Abbeville SC
Posts: 1,030
Charging system woes

87 r2500 01 5.3 4l60E with 25k miles on the swap. I have never been satisfied with the charging on this truck. Best I have ever seen is 13.8 at 2k rpm usually 13.2-13.4 at idle. Will not bring the battery back up if its weak and with the Headlights and AC the voltmeter plummets. I have wired it back to the stock wire from the lamp in the truck, I wired it originally to the PCM with no difference in results. This is the 3rd Alt. went from the low amp to the high amp unit first and the high amp unit had a bearing failure, but all charged approx. the same. Using a DVOM on the batt to get my readings. Is there a 1 wire regulator for these? Is there an old style alt that will fit the bracket? Thanks Jay
__________________
Current trucks:
(48 GMC100 320 inliner) Gone
(48 Suburban in pieces) Sold
87 GMC CCSB 5.3 4l60E Daily Driver

ECTA National record holder XO/PP

We never really grow up, we just learn how to act in public.
Big Port Jimmy 6 is offline   Reply With Quote
Old 06-30-2015, 08:35 PM   #2
clinebarger
Senior Member
 
Join Date: May 2009
Location: Fort Worth, TX
Posts: 6,370
Re: Charging system woes

It's most likely not the Alternator itself.

The Alternators job is to maintain the battery, Not to charge a weak/discharged battery.

Have you checked the voltage at the output post on the alternator, If it is showing 14 plus volts & the Battery is showing 13.2 volts....You have a Voltage drop (resistance) between the Battery & Alternator. I usually use at least an 8 gauge charge wire.
Don't forget that the Alternator is grounded through the bracket, A painted bracket will cause issues if all the mounting points are not cleaned.
clinebarger 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 02:08 AM.


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