one wire GM alternator - Page 3 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Electrical
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #31 (permalink)  
Old 02-08-2014, 06:02 PM
Registered User
 
Last wiki edit: Wheelbase database Last photo:
Join Date: Jan 2007
Location: Virginia
Posts: 3,506
Wiki Edits: 1

Thanks: 6
Thanked 143 Times in 130 Posts
Quote:
Originally Posted by EOD Guy View Post
Just to make it clear. You do NOT need a resistor or a light to get a GM 3 wire alt to work properly! You need a 12v source to excite the alt on the #1 terminal in order for it to produce juice, the #2 terminal will tell it how much to produce depending on the demand on the elec system.
Actually, for the SI-family alternators, you do. The resistance of the idiot light filament is the correct resistance. If you have a voltmeter with no idiot light, use about a 35 ohm resistor. And, by the way, if you spend $3 for a 35 ohm resistor, you've been ripped off. $0.30 is about the going rate for a low wattage version.

The CS130 alternators have this resistance built in. If you have an idiot light, simply connect that wire to the "L" terminal on the alternator. If you don't have a light, connect a switched 12V source to the "F" terminal. No resistor is needed on these, it's built into the "F" terminal.

    Advertisement
Reply With Quote Quick reply to this message
The Following User Says Thank You to joe_padavano For This Useful Post:
Y-Blockhead (02-08-2014)
Sponsored Links
Advertisement
 
  #32 (permalink)  
Old 02-08-2014, 06:12 PM
Y-Blockhead's Avatar
Registered User
 
Last photo:
Join Date: Nov 2013
Location: SoCal
Posts: 38
Wiki Edits: 0

Thanks: 8
Thanked 9 Times in 7 Posts
Thanks Joe. I have heard this many times about the need for a resistor if not using a indicator light but no one ever gives a value for the resistor needed.

Now for a question. What occurs when the light bulb burns out. Does the alternator not get "excited". In other words, will the battery charge with the bulb burned out? If not, can you install a resistor in parallel with the bulb for when it burns out it will still charge.

Thanks, just trying to learn something about I've always had questions about.
Reply With Quote Quick reply to this message
  #33 (permalink)  
Old 02-08-2014, 06:31 PM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 1,974
Wiki Edits: 0

Thanks: 1
Thanked 114 Times in 106 Posts
Joe, I respect your opinion.......but I have changed over many with the dash light to the SI style and many with out the dash light and have never needed the resistor. I have done a couple with hacked wiring and had to use a bulb to get it to work right, but I always thought it was due to the hacked wiring. Might be I just got lucky but it's has to be over 35 now.
Reply With Quote Quick reply to this message
  #34 (permalink)  
Old 02-09-2014, 02:19 AM
gearheadslife's Avatar
MentalMuffinMan
 
Last photo:
Join Date: Nov 2012
Posts: 1,978
Wiki Edits: 0

Thanks: 83
Thanked 222 Times in 209 Posts
Quote:
Originally Posted by EOD Guy View Post
Don't need to read anything, I have lots of experience and very familiar with alt wiring, none of my current vehicles have it, dozens of others I have wired don't have it. But if you want to do it then go ahead, nothing stopping you. I stand by.... if it's wired right then you don't need the extra hardware and if needed the diode will fix run-on. Nothing I've ever wired needed a diode or a resistor (55 to 73 era).
ok, have fun
Reply With Quote Quick reply to this message
  #35 (permalink)  
Old 02-09-2014, 04:18 AM
Registered User
 

Last journal entry: New Rev wheels and BFG KDW II tires
Last photo:
Join Date: May 2013
Location: South Central MN
Posts: 432
Wiki Edits: 0

Thanks: 59
Thanked 94 Times in 87 Posts
Quote:
Originally Posted by mud.man.rj View Post
Does Ford make a 1 wire, I don't believe so unless it is an aftermarket Ford style. Only diff for fitment is the Ford lug is longer and just need a short spacer to the block.
Ford uses a 7/16" bolt instead of a 3/8" bolt like GM does.
Reply With Quote Quick reply to this message
  #36 (permalink)  
Old 02-09-2014, 04:58 AM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 1,974
Wiki Edits: 0

Thanks: 1
Thanked 114 Times in 106 Posts
OK..... I not talking about the 130 series of alt as I've had little experience with them.

Gearhead how much voltage is on the wire leading into the #1 terminal on the alt? Could you please provide a link to your source that GM uses a resistor on the OEM wiring in all their cars, I can not find that info anywhere.

Last edited by EOD Guy; 02-09-2014 at 05:14 AM.
Reply With Quote Quick reply to this message
  #37 (permalink)  
Old 02-09-2014, 05:40 AM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 1,974
Wiki Edits: 0

Thanks: 1
Thanked 114 Times in 106 Posts
In old external regulators there were resistors, but they were used to regulate voltage and we weren't talking about external regulators.
Reply With Quote Quick reply to this message
  #38 (permalink)  
Old 02-09-2014, 06:02 AM
gearheadslife's Avatar
MentalMuffinMan
 
Last photo:
Join Date: Nov 2012
Posts: 1,978
Wiki Edits: 0

Thanks: 83
Thanked 222 Times in 209 Posts
Quote:
Originally Posted by EOD Guy View Post
In old external regulators there were resistors, but they were used to regulate voltage and we weren't talking about external regulators.
the idiot light is the RESISTOR.. and WHY every g.m. car with internal reg alt had one even if it has the gauge package with a volt gauge. and IS the reason when I went from a ext reg alt to a internal. I had to ADD a resistor to the circuit.. You clearly got lucky.. as the gm set up needs it to work correctly..
Reply With Quote Quick reply to this message
  #39 (permalink)  
Old 02-09-2014, 06:37 AM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 1,974
Wiki Edits: 0

Thanks: 1
Thanked 114 Times in 106 Posts
So where is your reference? And no I wasn't lucky. And you do not need a resistor for it to work correctly. Seems like there were many trucks that didn't have a light.

Last edited by EOD Guy; 02-09-2014 at 06:43 AM.
Reply With Quote Quick reply to this message
  #40 (permalink)  
Old 02-09-2014, 08:09 AM
gearheadslife's Avatar
MentalMuffinMan
 
Last photo:
Join Date: Nov 2012
Posts: 1,978
Wiki Edits: 0

Thanks: 83
Thanked 222 Times in 209 Posts
Quote:
Originally Posted by EOD Guy View Post
So where is your reference? And no I wasn't lucky. And you do not need a resistor for it to work correctly. Seems like there were many trucks that didn't have a light.
I'll go look up all the thread on the truck site/chevelle//nova/impala/etc sites when I have nothing better to do..
I know without a link it' isn't true to some.. you'll have to wait..
Reply With Quote Quick reply to this message
  #41 (permalink)  
Old 02-09-2014, 01:22 PM
T-bucket23's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Engine basic condition - how to check Last photo:
Join Date: Aug 2005
Location: Massachusetts
Age: 56
Posts: 5,051
Wiki Edits: 26

Thanks: 6
Thanked 92 Times in 78 Posts
Quote:
Originally Posted by EOD Guy View Post
I've never added a resistor nor a diode to get a GM alt working properly, the reason some people add those things is partly due to a poor wiring system, I some times refer to as a hack job when I'm fixing them.

If I'm wrong...... then why do new aftermarket wiring harnesses not come with a resistor or a diode? I know for a fact Painless doesn't.
This is correct. I got sick of arguing with people about the diode and resistor. They are both band aids for sub par wiring.
__________________
Artificial Intelligence is no match for Natural Stupidity



Chet
Reply With Quote Quick reply to this message
  #42 (permalink)  
Old 02-09-2014, 03:22 PM
mud.man.rj's Avatar
Registered User
 
Last photo:
Join Date: Oct 2010
Location: canada
Posts: 365
Wiki Edits: 0

Thanks: 0
Thanked 18 Times in 18 Posts
diode or not.

Don't need a diode for the 1 wire alt, they came on a multitude of non automotive things, mostly tractors and generators. They don't need a diode and I have used at least 5 one wire alts on my Muscle cars and trucks for many years, plus sold at least 30 of them without any issue which are still being used, some daily some not. Only issue was the pulley size at idle.
Reply With Quote Quick reply to this message
  #43 (permalink)  
Old 02-09-2014, 09:21 PM
Registered User
 

Last journal entry: Old guy's low cost Chev coup.
Last photo:
Join Date: Apr 2011
Location: Baytown, Texas
Posts: 66
Wiki Edits: 0

Thanks: 2
Thanked 2 Times in 2 Posts
Not throwing oppinion, just asking question for my knowledge (and action). Am running standard chev alternator on my '51 coup and it recently quit charging. Have ext regulator set up since built the car in 92/93. Only problem ever had with charging system was when I shorted hot wire to dash from too many connections on ign sw. I am seriously considering eliminating the external regulator, but need the feeds from the VR (r/field)to run alternator. The other (hack) system I have and want eliminate soon as can is amp guage runs parallel to charging system. Although it is not a direct link in the charging system, it is carrying the same amperage as the charging system. I haven't burned up the car yet, but that's probably just luck. maybe somebody can direct me to a source to learn how I can set up charging system without external VR. I'm thinking modern alternators have internal VR. But, they still need that 'r' and 'f' connector (relay/field) that come from the VR. Know there's a lot of experience out there, maybe can tap into it. When I built this thing, took sbc and all out of chev sedan and installed with charging system in my coupe. Didn't see any way to eliminate VR, and honestly didn't even think about it. Worked good as was. How's that saying go? If it aint broke, don't fix it. But, need to clean it up as have been having some problems lately, and think may be overcharging battery.
Reply With Quote Quick reply to this message
  #44 (permalink)  
Old 02-09-2014, 10:17 PM
Registered User
 

Last journal entry: New Rev wheels and BFG KDW II tires
Last photo:
Join Date: May 2013
Location: South Central MN
Posts: 432
Wiki Edits: 0

Thanks: 59
Thanked 94 Times in 87 Posts
Quote:
Originally Posted by fasteddy_1947 View Post
Not throwing oppinion, just asking question for my knowledge (and action). Am running standard chev alternator on my '51 coup and it recently quit charging. Have ext regulator set up since built the car in 92/93. Only problem ever had with charging system was when I shorted hot wire to dash from too many connections on ign sw. I am seriously considering eliminating the external regulator, but need the feeds from the VR (r/field)to run alternator. The other (hack) system I have and want eliminate soon as can is amp guage runs parallel to charging system. Although it is not a direct link in the charging system, it is carrying the same amperage as the charging system. I haven't burned up the car yet, but that's probably just luck. maybe somebody can direct me to a source to learn how I can set up charging system without external VR. I'm thinking modern alternators have internal VR. But, they still need that 'r' and 'f' connector (relay/field) that come from the VR. Know there's a lot of experience out there, maybe can tap into it. When I built this thing, took sbc and all out of chev sedan and installed with charging system in my coupe. Didn't see any way to eliminate VR, and honestly didn't even think about it. Worked good as was. How's that saying go? If it aint broke, don't fix it. But, need to clean it up as have been having some problems lately, and think may be overcharging battery.
This article will show how to rewire your system to an internally regulated alternator. Look into the 12si. For the money they are an excellent upgrade. Similar to the 10si but built with a few upgrades to help them perform better.

Chevy charging systems

Don't bother getting his kit. The special wire he talks about is SXL cross link wire. Worth getting but you can get a better deal from Del City Electronics.

http://www.delcity.net/store/Cross!Link-Wire/p_804928


Get rid of the amp gauge and replace it with a voltage gauge.

Last edited by 64SS327; 02-09-2014 at 10:23 PM.
Reply With Quote Quick reply to this message
  #45 (permalink)  
Old 02-10-2014, 04:12 AM
EOD Guy's Avatar
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Alabama
Posts: 1,974
Wiki Edits: 0

Thanks: 1
Thanked 114 Times in 106 Posts
It's pretty easy to eliminate the external regulator and switch over to an internal reg. I like the 12SI series because they are cheap and avail anywhere.

Basically you are going to remove the external reg from the system and jump the following wires together:

F terminal (blue?) to 4 terminal (brown?)
2 terminal (white?) to 3 terminal (red?)
The original hot wire from the junction block to the horn relay is to small and should be increased to a 8 gauge or run a new 10 gauge in addition to the old wire (two wires from the junction block to the horn relay)

F terminal or blue wire goes to the #1 terminal on the alt.
2 terminal or white wire goes to the #2 terminal on the alt.
These are easy to mix up when attaching a new pig tail, before you plug it into the alt do a static test....... hook up the battery, #2 on the pigtail should have 12v with the key off, #1 should have zero volts with the key off and 12v with the key on.

Terminal #1 from the alt goes to the one side of the idiot light on the dash. The other side of the idiot light goes to a switched 12v source (hot when the key is in the run position) This is the exciter wire and tells the alt to start producing juice. The idiot light does not get a ground wire, it gets a ground from the internal regulator in the alt when the alt isn't spinning. That's why it lights when the key is turned to run but the engine isn't running, and it goes out when the engine starts. You do not need a light if you choose not to, just a switched 12v source.

Terminal #2 from the alt goes to the hot side of the wiring system, normally it’s spliced into the hot feed leading to the fuse box. This is the sense wire, it tells the alt to produce more or less juice depending on the demands of your electrical system. Some people tie this to the output lug on the alt, it will work but you are not getting a true sense of the demand on the elec system. GM orig tied this into the system well away from the alt to take advantage of the long run of wire that acts like a buffer of sorts and measured a true demand on the system, with a 4" run you'd only get the demand at the alt, which prob would be about 13 ish volts, while the actual demand might be 14 volts...... alt would not increase production to compensate etc....

The large lug on the back of the alt is the output wire or charge wire and is normally tied directly to the pos post on the battery via a large gage battery cable.

On some installations the alt may need a ground cable, (I never use one etc….)

That's pretty much it, now if you have run-on (engine won't shut off when the key is turned off) you either have to clean up your wiring or install a diode on the #1 pigtail wire.

If you want to keep the orig look of the voltage reg, I saw a guy that gutted it and hid his splices inside.
Attached Thumbnails
Click image for larger version

Name:	12sialt.jpg
Views:	128
Size:	19.3 KB
ID:	120481  

Last edited by EOD Guy; 02-10-2014 at 04:23 AM.
Reply With Quote Quick reply to this message

Recent Electrical posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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 for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
wire terminal broke off 2-wire alternator bullheimer Electrical 3 10-11-2009 10:22 AM
One-wire to 3-wire Alternator change nova69 Electrical 2 09-05-2005 07:18 PM
one wire / three wire, alternator hookup 65truck Electrical 1 10-24-2003 03:59 AM
Alternator(1 wire vs 3 wire) Pro Street Electrical 1 06-11-2003 07:16 PM
2 Wire to 1 Wire Alternator bluesman123 Electrical 8 02-04-2003 12:06 AM


All times are GMT -6. The time now is 07:41 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.