E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Thread Tools Search this Thread Rate Thread Display Modes
Prev Previous Post   Next Post Next
Old 01-08-2013, 02:03 AM   #1
Registered User
Join Date: Jan 2006
Location: Cyprus
Posts: 6,555
My Ride: ESS TS2 320ci
Exclamation SOLVED: Voltage issue, need help determining if alternator problem

My brother in law's E46 2003 318i is experiencing some voltage/battery/alternator/wiring issues I believe.

Occasionally and completely random, the red battery light will turn on for a couple of seconds or even minutes, then go off. Using the OBC voltage option #9, I get the following readings

12.3v on Ignition on, engine not running, assume battery is ok with this?
14.1v on engine running/idle, no electrical equipment on
13.7v on engine running/idle with heater, lights, etc on

It also appears that when I start the car, it takes some seconds for the alternator to reach 14.1v, it starts from 13v and rises to 14.1 is that normal? Also, if I rev the engine and let the throttle off, voltage drops to 13.7v until the engine rpm stops to idle (750rpm).

Checked the wiring seem nice and tight. The car's also experiencing some odd behavior which I think is also related to voltage fluctuations, which is random DSC AND ABS lights on, random rear tailight out warning.

No CEL codes stored.
Car has 55000 miles


Last edited by paraklas; 03-15-2013 at 01:07 PM. Reason: Auto-save 1363370800
paraklas is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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 On
Censor is ON

All times are GMT -5. The time now is 11:55 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
(c) 1999 - 2016 performanceIX Inc - privacy policy - terms of use