The monitoring system is the charging system - Saab 9000 Bulletin Board - Saabnet.com
The banner above is an advertisment - if it asks you to download software, please ignore.
Site News -
[General | Members | C900 | 9000 | NG900 & OG93 | 93 | 95 | NG95 | 99 | Sonett | Vintage Models | Clubs | Other Cars | FAQs | Gifts | Member Photo Galleries | Member Directory | Classifieds | Manuals | *Buddy Registry | *Mileage Registry | Polls | What's New | Raffle | Photo of the Month | Sponsors]

9000 Bulletin Board
1985-1998 [Subscribe to Daily Digest]
(Search Author's Posts: e.g. Keyword:username)*Members Only

[Main 9000 Bulletin Board | BBFAQ | Prev by Date | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
The monitoring system is the charging system
Like This Post: - Subscribe to Daily Digest for this Bulletin Board
Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Mon, 4 May 2009 04:00:34 Share Post by Email
In Reply to: Didn't get stranded, but problem persists, techlectic, Sun, 3 May 2009 10:48:33
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup

The battery light is an integral part of the charging system. An alternator is (kinda, sorta) like a generator, but a generator has permanent magnets. An alternator has electromagnets, and electromagnets need current to work. The electromagnets are called Field Coils.

When you first turn the key ON, current flows through the key, through the Battery light, and into the Field Coils through the D+ connection on the alternator, to ground. This energizes the field coils and creates a magnetic field. It also turns on the Battery light, because current is flowing through it.

When the engine starts to spin, it spins the alternator armature, and since there is a magnetic field,the armature produces voltage and current. When it is spinning fast enough, it is producing enough voltage that the VR starts putting current into the field coils. Since the VR is driving the field coils, the current in the Battery light drops to zero, and the light goes out.

So if the battery light comes on, it means the VR isn't driving the field coils, and the alternator isn't producing more voltage than the battery - the battery is now running the car, a bad thing.

The EDU and the battery light agree, so you've got a charging problem. Yes, most likely bad brushes, best fixed by replacing the VR.

posted by 76.231.241...

Posts in this Thread:
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

Name: Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
E-Mail: (Optional)
Re-Enter E-Mail: (Confidential & Secure - Not revealed to other users!)
Note: Please check your spam folder for BB responses.

Subject:

Posting rules are simple - No for sale/wanted ads may be posted here - use the site classifieds.
You may not cross-post your message to multiple BBs.
Not permitted: political/religious topics and being disrespectful (personal attacks, insults, etc...).
 Site Members do not see any red text, inline ad links, bottom of page anchor ads, box ads, or anti-spam check.

Message: (please no for sale/wanted classifieds - post those in the Saabnet.com Classifieds)
Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).

Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post above, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).
Optional Link: (e.g. http://www.saabnet.com/)
Link Title: (Optional)
Optional Photo/Image Link: (e.g. http://www.saabnet.com/img.jpg)
Photo/Image to Upload: (Please be patient while file uploads)



StateOfNine.com
SaabClub.com
Jak Stoll Performance
M Car Covers
Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2024 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right. Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY. Classifieds are to be listed in The Saab Network Classifieds pages. This is a problem solving forum for over 250,000 Saab owners, so expect to see problems discussed here even though our cars are generally very reliable. This is not an anything goes type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the Saabnet.com Mission and Purpose Page. Please remember that you are not anonymous. Site Contact | Site Donations | Other Sites by SP - Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot


Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all the Site Membership Benefits!