Ground wire for Alternator - Team Camaro Tech
Electrical & Wiring Troubleshooting electrical.

LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old Apr 16th, 06, 06:37 AM Thread Starter
Senior Tech
Join Date: Nov 2005
Location: Sinking Spring, PA
Posts: 135
Ground wire for Alternator

Hey guys, I hate to ask the same question twice, did a search and did not find an answer. So here goes my stupid question for the day.

Should there be a ground wire from the alternator to the body? I have a '69 big block with the stock alternator. The alternator has a post on the back for a ground wire but obviously no wire is connected and everything works fine.

Thoughts? Thanks.

'69 SS396, X22, 50/50, 729
3rail is offline  
Sponsored Links
post #2 of 4 (permalink) Old Apr 16th, 06, 07:41 AM
Gold Lifetime Member
Join Date: Dec 1999
Location: Yorkville, Illinois USA
Posts: 22,121
Re: Ground wire for Alternator

I've seen lotsa alternators with a ground post on the back, not a one with anything on it.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
New website for my vert is coming together. Do ya like the slide show on the home page?
JimM is offline  
post #3 of 4 (permalink) Old Apr 16th, 06, 01:04 PM
Senior Tech
Join Date: Jun 2005
Location: Sunny So. Cal
Posts: 3,064
Re: Ground wire for Alternator

The Alternator is grounded already via the bracket to the engine block. My guess is the ground terminal is there as an extra source in case the body ground is not sufficient enough in certain applications.

67 RS Camaro 327/ 350 Holley 650cfm > Edelbrock Performer Intake > Pertronix Ignition > Accel Super Stock Coil and Wires > Hedman Hedders > Hotchkis Performance Springs > 15" Rallys all around

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Camaro buds until the end!!!
Camaro Dave is offline  
post #4 of 4 (permalink) Old Apr 16th, 06, 04:34 PM
Senior Tech
Join Date: Dec 2002
Location: Saint Louis, Missouri
Posts: 1,123
Re: Ground wire for Alternator

You need some kind of good electrical connection between the battery negative terminal or the engine to the body of the car. Some have a wire off of the battery negative terminal to the fender while others have this and a flat braided type wire from the back of the engine to the firewall. Whether you use this threaded hole on the alternator to the body of the car or do it a different way you do need to tie the body of the car to the rest of the cars electrical system.
Anytime I put on a high output alternator on customer's cars I use the threaded hole in the alternator case for a ground to go between it and the battery as I am also running a new larger wire from the output post of the alternator to the positive post on the battery and I can run them together over to the battery. Since a stock alternator and the factory wiring is designed to use a minimum wire size anytime you upgrade to a higher output source you also need to upgrade the ground connections. It all has to work as a looped type system. If you have an alternator or an amplifier in a vehicle most people run a big enough power wire but a lot of time fail to address the return path (the grounds). If a ground path is insuffecient this becomes a choke and will not allow the electrical device to work properly.

1974 Spirit Of America Nova (being restored), 1973 Nova Custom, 1968 Chevy II (Garage Find 2012)

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
SOA-Nova is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
ground wire location? homiebryant17 Electrical & Wiring 0 Nov 5th, 05 06:48 PM
PO 300 301 302 OBD II 3L 4P Bench Racing 9 May 6th, 05 08:02 PM
Ground wire for dash? Tucson '67 RS Electrical & Wiring 2 Feb 14th, 04 06:39 AM
welding....need help 69ss350camaro Body Shop 3 Apr 3rd, 03 02:20 PM
Expanded MARTINSR Body Shop 11 Jan 15th, 03 02:57 PM

Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome