Wiring help- new alternator - Team Camaro Tech
Electrical & Wiring Troubleshooting electrical.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 24 (permalink) Old May 20th, 11, 12:51 PM Thread Starter
Senior Tech
 
Join Date: Jul 2005
Location: Tuscaloosa, AL
Posts: 145
Wiring help- new alternator

I have a 68 with a/c which in the past has been upgraded to a 10si 63 amps. Along wi the upgrade the wiring from the alternator to the battery was upgraded to 8 gauge. the alt is loosing a bearing so I'm going to upgrade to a 12 si 93 amps. My question is about wiring.

1. Should I upgrade to 4 gauge with an 80 amp fuse?

2. If I re-wire can I run a new line directly from the alt to the battery bypassing the horn relay and the passenger side junction box but keep the old 8 gauge line connected to the battery kind of letting the current backfill the horn relay? I was thinking that the relay and/or junction box would be weak links for the beefed up amps.

Thanks
sthoma10 is offline  
Sponsored Links
Advertisement
 
post #2 of 24 (permalink) Old May 20th, 11, 01:08 PM
Senior Tech
Al
 
Join Date: Nov 2002
Location: Vancouver, USA
Posts: 10,512
Re: Wiring help- new alternator

Do you have a lot of accessories that draw a lot of current?

The diagram I have seen that makes the most sense is to run an 8ga wire (witha 12ga fusible link) from the stud on the alt to the horn relay for remote sensing, and connect the original 10ga sense wire that originally went between the alt and the horn relay to the junction block ahead of the battery, giving you two 10ga wires between those two. http://www.hotrod.com/techarticles/m.../photo_22.html


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BPOS is offline  
post #3 of 24 (permalink) Old May 20th, 11, 05:34 PM
Senior Tech
Steiner
 
Join Date: Mar 2009
Location: Lyman, SC
Posts: 8,348
Re: Wiring help- new alternator

That's what I did (one wire alt).... Heaviest premade cable the parts store had from alt to battery, then an auto reset circuit breaker between the battery and horn relay instead of fusible link. Left the original cable to the horn relay since I put in a fused auxiliary feed coming off the battery for new stuff.

'69 Camaro
Dart 400-AFR 195-224/224 HR-Powerjection III TB with F.A.S.T. Sportsman XFI
TKO 600-Moser 3.42-Detroit Truetrac
500hp/538lbft

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

'69 Camaro Beater-SFT 327-M20-Moser 4.10-sold
'02 Z/28 vert-stock-sold and totaled
Steiner is offline  
 
post #4 of 24 (permalink) Old May 20th, 11, 10:50 PM
Gold Lifetime Member
Larry
 
larryh56's Avatar
 
Join Date: Oct 2008
Location: Central Washington
Posts: 1,503
Re: Wiring help- new alternator

Check out this article: http://www.madelectrical.com/electri...evymain1.shtml
Using your horn relay as the main power distribution point as Al said is a good way to go.
PS I have read you can't buy stuff from MAD Electrical any more.

68 RS Coupe 355/350 TH, Detroit Speed, Hotchkis, Vintage Air, 8.5" 3.42 posi 10-bolt, MagnaFlow 2 1/2" exhaust, etc.

"The public cannot be too curious concerning the characters of public men."
Samuel Adams
larryh56 is offline  
post #5 of 24 (permalink) Old May 21st, 11, 06:16 AM
Senior Tech
 
Join Date: Dec 2001
Location: Fairfield, CA
Posts: 6,246
Re: Wiring help- new alternator

I don't understand why these diagrams include a fusible link in the alternator wire. The alternator is incapable of putting out enough current to fuse the wire.

"For those that will fight for it...FREEDOM ...has a flavor the protected shall never know."
Semper Fi! L/Cpl Edwin L. "Tim" Craft, B Co 3rd AT's, Khe Sanh Combat Base, February, 1968
onovakind67 is offline  
post #6 of 24 (permalink) Old May 21st, 11, 06:49 AM
Gold Lifetime Member
Mike
 
prostreet69camaro's Avatar
 
Join Date: Jul 2003
Location: Spring Texas
Posts: 5,580
Re: Wiring help- new alternator

Quote:
Originally Posted by larryh56 View Post
Check out this article: http://www.madelectrical.com/electri...evymain1.shtml
Using your horn relay as the main power distribution point as Al said is a good way to go.
PS I have read you can't buy stuff from MAD Electrical any more.
Mad Electrical has some articles on there website. You want the alternator to sense the load. The alternator will control itself to charge the battery as needed.

If you have circuits running from the battery to like fans, fuel pumps, etc, the alternator will not sense the load. So it will not adjust the voltage to charge the battery as the battery is depleted.

Mike
69 Camaro Prostreet - purple w/ghost flames , 502 w/ 871 blower


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
prostreet69camaro is offline  
post #7 of 24 (permalink) Old May 21st, 11, 06:52 AM
Gold Lifetime Member
Mike
 
prostreet69camaro's Avatar
 
Join Date: Jul 2003
Location: Spring Texas
Posts: 5,580
Re: Wiring help- new alternator

Quote:
Originally Posted by onovakind67 View Post
I don't understand why these diagrams include a fusible link in the alternator wire. The alternator is incapable of putting out enough current to fuse the wire.
The mad electrical doesnt show a fusible link on the alternator wire. It shows a #14 from the battery to the horn realy and #16 to the main power wire going inside the car.

Mike
69 Camaro Prostreet - purple w/ghost flames , 502 w/ 871 blower


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
prostreet69camaro is offline  
post #8 of 24 (permalink) Old May 21st, 11, 03:00 PM Thread Starter
Senior Tech
 
Join Date: Jul 2005
Location: Tuscaloosa, AL
Posts: 145
Re: Wiring help- new alternator

Thanks for the comments and suggestions. I wonder why Mad electric suggests 8 gauge to the horn relay but nothing further? Is the main draw only to this point and not the battery?
sthoma10 is offline  
post #9 of 24 (permalink) Old May 21st, 11, 04:25 PM Thread Starter
Senior Tech
 
Join Date: Jul 2005
Location: Tuscaloosa, AL
Posts: 145
Re: Wiring help- new alternator

But mad electric includes a 12 gauge fusible link in their alternator wiring kit for high amp upgrades!
sthoma10 is offline  
post #10 of 24 (permalink) Old May 21st, 11, 10:59 PM
Gold Lifetime Member
Larry
 
larryh56's Avatar
 
Join Date: Oct 2008
Location: Central Washington
Posts: 1,503
Re: Wiring help- new alternator

Quote:
Originally Posted by sthoma10 View Post
Thanks for the comments and suggestions. I wonder why Mad electric suggests 8 gauge to the horn relay but nothing further? Is the main draw only to this point and not the battery?
This is to ensure that max power is being delivered to the horn relay and this is where they recommend you draw power for the accessories. There is a fusible link for the wire attaching to the batt terminal on the alternator. That wire is always hot and if it shorted the fusible link will burn as all the power for the car goes through that wire except when the car is starting.

68 RS Coupe 355/350 TH, Detroit Speed, Hotchkis, Vintage Air, 8.5" 3.42 posi 10-bolt, MagnaFlow 2 1/2" exhaust, etc.

"The public cannot be too curious concerning the characters of public men."
Samuel Adams
larryh56 is offline  
post #11 of 24 (permalink) Old May 22nd, 11, 05:59 AM
Senior Tech
 
Join Date: Dec 2001
Location: Fairfield, CA
Posts: 6,246
Re: Wiring help- new alternator

Quote:
Originally Posted by prostreet69camaro View Post
The mad electrical doesnt show a fusible link on the alternator wire. It shows a #14 from the battery to the horn realy and #16 to the main power wire going inside the car.
I was referring to the above linked drawing - http://www.hotrod.com/techarticles/m.../photo_22.html

Quote:
Originally Posted by sthoma10 View Post
But mad electric includes a 12 gauge fusible link in their alternator wiring kit for high amp upgrades!
Why would they do this?

"For those that will fight for it...FREEDOM ...has a flavor the protected shall never know."
Semper Fi! L/Cpl Edwin L. "Tim" Craft, B Co 3rd AT's, Khe Sanh Combat Base, February, 1968
onovakind67 is offline  
post #12 of 24 (permalink) Old May 23rd, 11, 05:42 AM
Senior Tech
Greg
 
Join Date: Jan 2004
Location: Winston Salem, NC
Posts: 1,515
Re: Wiring help- new alternator

Quote:
Originally Posted by BPOS View Post
Do you have a lot of accessories that draw a lot of current?

The diagram I have seen that makes the most sense is to run an 8ga wire (witha 12ga fusible link) from the stud on the alt to the horn relay for remote sensing, and connect the original 10ga sense wire that originally went between the alt and the horn relay to the junction block ahead of the battery, giving you two 10ga wires between those two. http://www.hotrod.com/techarticles/m.../photo_22.html
The diagram above is what I did. To the OP, what electrical accessories do you run? I have electric fan, fuel pump, water/meth pump and the 12si 78 amp alternator works plenty fine for me. My fan is not a real high draw one though. Some fans alone can draw 40 amps.

69 Camaro, 3650lbs., 400ci, TH400, Coan 10" converter, 3.50 gear
D1SC, pump gas, street car, Water/Meth injection
1.302 60', 5.956 @ 116.4 Super Sniper EFI 2019
Greg O is offline  
post #13 of 24 (permalink) Old May 23rd, 11, 06:50 AM Thread Starter
Senior Tech
 
Join Date: Jul 2005
Location: Tuscaloosa, AL
Posts: 145
Re: Wiring help- new alternator

Thanks. All I have now now is an A/C car with HEI but with the alternator going I had wanted to have in place a charging system that could handle any upcoming additions like fans.
sthoma10 is offline  
post #14 of 24 (permalink) Old May 23rd, 11, 08:29 AM
Senior Tech
Al
 
Join Date: Nov 2002
Location: Vancouver, USA
Posts: 10,512
Re: Wiring help- new alternator

Quote:
Originally Posted by onovakind67 View Post
I was referring to the above linked drawing - http://www.hotrod.com/techarticles/m.../photo_22.html



Why would they do this?
Good question. The factory used a fusible link from the junction block to the battery+, and that is not shown in the diagram.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BPOS is offline  
post #15 of 24 (permalink) Old May 23rd, 11, 09:43 AM
Senior Tech
Greg
 
Join Date: Jan 2004
Location: Winston Salem, NC
Posts: 1,515
Re: Wiring help- new alternator

Quote:
Originally Posted by sthoma10 View Post
I have a 68 with a/c which in the past has been upgraded to a 10si 63 amps. Along wi the upgrade the wiring from the alternator to the battery was upgraded to 8 gauge. the alt is loosing a bearing so I'm going to upgrade to a 12 si 93 amps. My question is about wiring.

1. Should I upgrade to 4 gauge with an 80 amp fuse?

2. If I re-wire can I run a new line directly from the alt to the battery bypassing the horn relay and the passenger side junction box but keep the old 8 gauge line connected to the battery kind of letting the current backfill the horn relay? I was thinking that the relay and/or junction box would be weak links for the beefed up amps.

Thanks

1- no need to upgrade to 4 AWG. 8 should be more than plenty

2- Do not do this, they are not weak links. Also, when you add fans later on, etc. wire them with a relay and have the main power feed come from the horn relay buss bar for optimal performance.

With just AC and HEI, a 78 amp would still give you room to grow with an electric fan IMO.

69 Camaro, 3650lbs., 400ci, TH400, Coan 10" converter, 3.50 gear
D1SC, pump gas, street car, Water/Meth injection
1.302 60', 5.956 @ 116.4 Super Sniper EFI 2019
Greg O is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

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

Password:


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:
OR

Log-in










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



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