The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Electrical

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 12-26-2015, 12:13 PM   #1
Chevy 350 Fan
Registered User
 
Join Date: Jan 2015
Location: Channahon IL
Posts: 50
One Wire Alternator Conversion

Hey guys I'm a senior in high school, I have a 72 GMC C20. I installed an American Auto wire kit on this truck. The one part I have yet to figure out is the alternator. I think I would rather run an internally regulated because I had nothing but problems with the externally regulated. So I was going to go to auto zone and get an alternator for like an 80's truck. Now my question is how do I hook it up? I no longer have the wires for the regulator set up (truck caught on fire few months ago and I gutted all that ****) So all I have is the brown wire coming out of the firewall connector. According to my diagram and what I remember there are 4 wires for the regulator: blue white, red and brown. From what I've read you connect white to red and brown to blue. So since I'm starting from scratch here in my mind I think I ought to be able to run the brown wire straight to the alternator and splice the red power wire coming off the back and have it go to the other connector on the side of the alternator and then the other lead go to the battery. does that sound acceptable to you guys? Here's a picture of a wiring diagram I found on how to do it. FYI I do have the factory diagram as well and wire colors match up. let me know what you think
Thanks!
Chevy 350 Fan is offline   Reply With Quote
Old 12-26-2015, 12:22 PM   #2
Chevy 350 Fan
Registered User
 
Join Date: Jan 2015
Location: Channahon IL
Posts: 50
Re: One Wire Alternator Conversion

Here is that picture
Attached Images
 
Chevy 350 Fan is offline   Reply With Quote
Old 12-26-2015, 04:30 PM   #3
Chevy 350 Fan
Registered User
 
Join Date: Jan 2015
Location: Channahon IL
Posts: 50
Re: One Wire Alternator Conversion

Here's another question I got. The standard alternator is 63 amp. Do you think that that would be enough? I'm running a built 350 corvette motor makes 500 HP. I'm running MSD ignition (6AL with a blaster coil) Holley red electric fuel pump (says it only draws 2 amps) and electric cooling fans (25 amps). I might get an electric water pump also at some point. The electric water pump I was considering draws 20 amps it says. In addition to those mods there is still all the stock equipment: lights, wipers etc. so do you think 63 amp is going to be enough or should I reconsider my approach here?
Chevy 350 Fan is offline   Reply With Quote
Old 12-26-2015, 06:11 PM   #4
RodnRudy
Senior Member
 
RodnRudy's Avatar
 
Join Date: Oct 2014
Location: New Palestine In
Posts: 930
Re: One Wire Alternator Conversion

I'd get a 100 AMP alt. minimum. Also the red power wire from the alt. to the battery should be at least 10 ga.
RodnRudy is offline   Reply With Quote
Old 12-26-2015, 06:40 PM   #5
Already Gone
70+ ( Old Skool Club )
 
Already Gone's Avatar
 
Join Date: Nov 2003
Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,070
Re: One Wire Alternator Conversion

I'd check out this thread and do little thinking before you go to one wire alternator. There are some concerns going to one wire alternator on our trucks.

http://67-72chevytrucks.com/vboard/s...23#post7387223


http://www.madelectrical.com/electri...hreewire.shtml
__________________
1972 C10 Custom/Deluxe 613 Highlander 406/700R4
1999 White Tahoe LS 4x2 with Z56 Police Package
1992 K1500 GMC Suburban

Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601

" 4 Things When Used are Gone Forever "

" A Word After it is Said - A Missed Opportunity - Time once Passed - Trust after its Lost "


RIP Charlie Watts 1941 - 2021
Already Gone is offline   Reply With Quote
Old 12-26-2015, 07:13 PM   #6
LSGarage
Registered User
 
LSGarage's Avatar
 
Join Date: Aug 2005
Location: Mechanicsburg, PA
Posts: 86
Re: One Wire Alternator Conversion

Read Mad Electrical, learn it, know it. Do not go the one wire route, just my 2 cents worth
__________________
67 GMC 4x4, 305 V-6, 4-spd
86 S-10, 2.8 2WD LWB
01 Suburban (family hauler)
13 Honda CRV (wife's wheels)
03 Malibu (daughter’s car)
LSGarage is offline   Reply With Quote
Old 12-26-2015, 07:31 PM   #7
Chevy 350 Fan
Registered User
 
Join Date: Jan 2015
Location: Channahon IL
Posts: 50
Re: One Wire Alternator Conversion

My ignorance is going to show here so please bear with me: I thought an internally regulated alternator was a one wire alternator I've never heard of 3 wire. Would you mind explaining the difference? I did some research, looked into those links and from what I understand a one wire voltage is sensed at the alternator and 3 wire it is sensed at another location???? (I would assume external v regulator) but that couldn't be the case because then it wouldn't be internally regulated. Maybe posting a wiring diagram would help. I'm sorry my knowledge is a little lacking on this subject haha, I just don't want to fry anything that I worked really hard to buy and install.Thanks for the replies guys!
Chevy 350 Fan is offline   Reply With Quote
Old 12-26-2015, 08:10 PM   #8
ray_mcavoy
Registered User
 
Join Date: Nov 2009
Location: Sherman, ME
Posts: 2,350
Re: One Wire Alternator Conversion

Quote:
Originally Posted by Chevy 350 Fan View Post
My ignorance is going to show here so please bear with me: I thought an internally regulated alternator was a one wire alternator I've never heard of 3 wire. Would you mind explaining the difference? I did some research, looked into those links and from what I understand a one wire voltage is sensed at the alternator and 3 wire it is sensed at another location???? (I would assume external v regulator) but that couldn't be the case because then it wouldn't be internally regulated.
Externally vs. internally regulated just describes the physical location of the voltage regulator ... not where the regulator is sensing the voltage.

A "3 wire" alternator is basically just a stock internally regulated alternator. However, you probably haven't heard it called that because the term "3 wire" isn't all that common.

As the name implies, a "1 wire" alternator only has 1 wire to hook up to the vehicle's electrical system. But because of that, it can't compensate for voltage drop in the charging system wiring due to it only sensing the voltage at it's own output terminal. And a 1 wire alternator also lacks the ability to operate a warning light.
ray_mcavoy is offline   Reply With Quote
Old 12-27-2015, 10:38 AM   #9
gmachinz
Account Suspended
 
Join Date: Jun 2011
Location: Des Moines, IA.
Posts: 4,143
Re: One Wire Alternator Conversion

I've provided a lot of harnesses for various swaps like this. I'd suggest getting a CS alternator for the amount of accessories you're planning to run. Go to a parts store and have them pull down one for a 1988 Olds Firenza 2.0FI. It has a serpentine pulley that can easily be swapped for your v-belt pulley. Then, modify the wiring for a CS alternator and you're all set-this alternator is a small case, 105A alternator and features 12 and 6 clocking.

I'm a bit confused-did your under hood wiring catch fire before or after your AAW install? Do you have a good harness to use still or do you need to go with a CS specific alternator add-on harness section?
gmachinz is offline   Reply With Quote
Old 12-27-2015, 12:19 PM   #10
vince1
Registered User
 
Join Date: Jan 2013
Location: Calgary Alberta
Posts: 1,162
Re: One Wire Alternator Conversion

From what I understand if you order a CS130 for an 89 Pontiac Safari it comes with a V pulley. An advantage of the CS series is that they charge so much better at low RPM. You would need the PL(I/F)S connector with it. Your brown wire would go to L for lamp and the S for sense could go where you want to sense the voltage, or if you want more simplicity, just put it to the output post.

if you want to go cheap like me, get them from the auto wreckers. I quite often find them brand new looking with a recent overhaul tag on them. Serpentine pulleys can be swapped out for V pulleys. There are lots of different mounting options so look for one of the smaller ones with the lugs 180 degrees apart and 6.6" across. I always keep a spare and if they need one offer them at cost to local club members.
vince1 is offline   Reply With Quote
Old 12-27-2015, 01:40 PM   #11
Chevy 350 Fan
Registered User
 
Join Date: Jan 2015
Location: Channahon IL
Posts: 50
Re: One Wire Alternator Conversion

Quote:
Originally Posted by gmachinz View Post
I'm a bit confused-did your under hood wiring catch fire before or after your AAW install? Do you have a good harness to use still or do you need to go with a CS specific alternator add-on harness section?
No the whole truck caught on fire when I was driving her to school in the spring hahaha. I spent my summer redoing her. she's just about finished now. just needs a few things ie: Alternator lol
Chevy 350 Fan is offline   Reply With Quote
Old 12-27-2015, 01:42 PM   #12
Chevy 350 Fan
Registered User
 
Join Date: Jan 2015
Location: Channahon IL
Posts: 50
Re: One Wire Alternator Conversion

Thanks for all the replies and suggestions guys! ill take them all into consideration.
Colton
Chevy 350 Fan is offline   Reply With Quote
Old 12-27-2015, 06:11 PM   #13
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,703
Re: One Wire Alternator Conversion

Quote:
Originally Posted by Chevy 350 Fan View Post
Thanks for all the replies and suggestions guys! ill take them all into consideration.
Colton
This is how simplistic the conversion is.
You know which wire is the brown exciter wire for the alternator so just connect it as shown below.

For the late eighties SI 12.


Name:  ammetershunt12si.jpg
Views: 7524
Size:  29.1 KB



And for the CS 130s and up

Name:  ammetershuntCS130.jpg
Views: 6862
Size:  30.6 KB

You might also check out the thread link in post 5 where we explain how to wire the two. If you intend to retain the battery gauge function in your gauge dash then you will have to wire the gauge as shown.
__________________
VetteVet

metallic green 67 stepside
74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

Growing old is hell, but it beats the alternative.
VetteVet is offline   Reply With Quote
Reply

Bookmarks

Tags
alternator, one wire conversion, wiring

Thread Tools
Display Modes

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 Off

Forum Jump


All times are GMT -4. The time now is 06:35 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com