One wire alternators
Thread Starter
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
One wire alternators
What is required to convert to a one wire alternator like:
http://www.cantonracing.com/alternat...ternators.html
http://www.cantonracing.com/alternat...ternators.html
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Why would you want to? It's an inferior system.
http://www.madelectrical.com/electri...hreewire.shtml
http://www.madelectrical.com/electri...hreewire.shtml
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Why would you want to? It's an inferior system.
http://www.madelectrical.com/electri...hreewire.shtml
http://www.madelectrical.com/electri...hreewire.shtml
The one wire takes it's reference voltage off the alternator not back under the dash were the voltage has dropped off considerabley.
An external reference say under the dash and feed back to the alternator would be good.
The back of a one wire alternator might read 14 volts but under the dash it might be 12 because of the long small wire feeding the fuse panel. If you had a feed back loop the referenced off the fuse block and pushed that voltage to 14 that would be alot better. In that case the alternator might need to boost it's voltage to 15 or 16
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Guru, Batty's got it right, I fought this very thing with a '70's era vette type alt on a Chebby boat yesterday and today too....
one wire alts are good for marine apps, but only on smaller engines....with this 350 V8, I found the typical car wiring was far superior...i'ts to do with at what rpm the thing charges at, and when it stops charging at what rpm....
it's in that regulator, and dependant on ALTERNATOR rpm more than engine rpm...belts/ratios/etc...loads...
Yeh, the onewire will get you out to cruising speed at engine of 2500 rpm or better, and so charge hell outta that DEEEEEEP cycle MARINE battery.....but for a car stuck in traffic for hours on end....
gimme 3 wire....
this above without getting toooo techy...I would have to go back to the schematics and crap to explain any further....I just remember the practical hookup knowledge...
one wire alts are good for marine apps, but only on smaller engines....with this 350 V8, I found the typical car wiring was far superior...i'ts to do with at what rpm the thing charges at, and when it stops charging at what rpm....
it's in that regulator, and dependant on ALTERNATOR rpm more than engine rpm...belts/ratios/etc...loads...
Yeh, the onewire will get you out to cruising speed at engine of 2500 rpm or better, and so charge hell outta that DEEEEEEP cycle MARINE battery.....but for a car stuck in traffic for hours on end....
gimme 3 wire....
this above without getting toooo techy...I would have to go back to the schematics and crap to explain any further....I just remember the practical hookup knowledge...
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I agree, the one wire alternators are good for charging a battery but not running an entire electrical system. I have the one wire alternator and am sorry I went that route.
The one wire takes it's reference voltage off the alternator not back under the dash were the voltage has dropped off considerabley.
An external reference say under the dash and feed back to the alternator would be good.
The back of a one wire alternator might read 14 volts but under the dash it might be 12 because of the long small wire feeding the fuse panel. If you had a feed back loop the referenced off the fuse block and pushed that voltage to 14 that would be alot better. In that case the alternator might need to boost it's voltage to 15 or 16
The one wire takes it's reference voltage off the alternator not back under the dash were the voltage has dropped off considerabley.
An external reference say under the dash and feed back to the alternator would be good.
The back of a one wire alternator might read 14 volts but under the dash it might be 12 because of the long small wire feeding the fuse panel. If you had a feed back loop the referenced off the fuse block and pushed that voltage to 14 that would be alot better. In that case the alternator might need to boost it's voltage to 15 or 16
YES, Norval, what you say is correct, but it goes a bit further than that, even.....crazy....
beeleemee when I say....been there done that on several cars, including this '72 vette.....
when reveiwing the MERCRUISER wiring diagrams....they never did referr to a resistor wire OR light bulb for the discharge/sense side of the built in regualtor....which is a tech error on their part....maybe just documentation...but at any rate, I been there done that, and wired the thing right just this morning....put in a 12 volt dash light in the correct circuit.....and fed the other wire with harness voltage about 3' away from the alt. output....
point being at 1000 engine rpm the thing charges the battery....
and do't drop off....
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
One wire alternators are for simple street rods not for a full charging system. Not recommended for Corvettes but for some reason a popular change for those that need something easy and new to install and add to a list of changes prominently displayed at local car shoes. Listen to the advice given by all preceding this comment and use your money for something else. Maybe a gift for the lady and who knows you could even be rewarded. 
Veteran
Joined: Oct 2005
Posts: 1,284
Likes: 81
From: Nashville, TN
I made the mistake of going to the one wire a few years ago. After a couple of long trips and not having enough juice to start back up once stopped, I gave it away. I am back to the stock set up with a power master alt. The one wire set up was just not doing the trick.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
Strange,
I just put one on my car and went from output of 12.47 to 14.27 and the battery went from the same up to 13.87, checked headlites and gained 1 volt and brighter.
I do recommend an 8 gauge charging wire from the alt to the batt cable on the starter.
I just put one on my car and went from output of 12.47 to 14.27 and the battery went from the same up to 13.87, checked headlites and gained 1 volt and brighter.
I do recommend an 8 gauge charging wire from the alt to the batt cable on the starter.
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
I agree with the others that say you should stick with a 3-wire system.
Here is a good link explaining the differences:
http://www.madelectrical.com/electri...hreewire.shtml
Here is a good link explaining the differences:
http://www.madelectrical.com/electri...hreewire.shtml
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
Here's Durango's writup on a CS alternator swap.
http://photos.imageevent.com/durango...%20Install.pdf
I just did this last week. Got a 105 amp alternator for $80 at autozone with lifetime warranty. Tell them you want an alt. off an '87 vette with 350 ci engine, its a direct replacement... v belt pulley, and the same regulator connector.
http://photos.imageevent.com/durango...%20Install.pdf
I just did this last week. Got a 105 amp alternator for $80 at autozone with lifetime warranty. Tell them you want an alt. off an '87 vette with 350 ci engine, its a direct replacement... v belt pulley, and the same regulator connector.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I"m sorry, BUT, I HAD my fill of 3X alternators in the 3 years I had my '87 Vette, that damn CS130 sucked.....course this was 12 years ago, and maybe they have improved on them, but maybe NOT, so for MY porposise I put on a SI17 comes off a '79 Seville with rear window defogger....supposed 108 amp rating....same wiring slightly larger diameter...it works.....I run Camaro headlights/a-c/driving lights/TPI, C4 blower, 850 idle speed (computer), and never runs outta juice even with the Dual Spals cranked up via relay controller--full drain....now I do have to admit exchanging the alt with AZone 2x to get a good one, but this last one has been on the car 2+ years now....
one thing I do recommend though, is to pull any alt apart and tighten up all the bolts....especially the output stud connections....they never tighten them adequately, so it's vibrating loose, and you get lousey connections....famous rebuilders lack of QC......been that way for decades, don't ask me why.....
one thing I do recommend though, is to pull any alt apart and tighten up all the bolts....especially the output stud connections....they never tighten them adequately, so it's vibrating loose, and you get lousey connections....famous rebuilders lack of QC......been that way for decades, don't ask me why.....
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,353
From: Santa Ana CA
I've been using a 1-wire on my '64 with absolutely no problems at all except that my amps gauge doesn't seem to swing as far as it used to.
A simple hook up too. Just connect the red wire to your battery, (just tuck the old plug aside or snip the wires) and your done. I also connected the ground wire as it was right there (even though it is grounded through the chassis.
Mine is rated for 100 amps and I use an Optima Yellow Top. I never have a problem with low charge rates.
A simple hook up too. Just connect the red wire to your battery, (just tuck the old plug aside or snip the wires) and your done. I also connected the ground wire as it was right there (even though it is grounded through the chassis.
Mine is rated for 100 amps and I use an Optima Yellow Top. I never have a problem with low charge rates.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I've been using a 1-wire on my '64 with absolutely no problems at all except that my amps gauge doesn't seem to swing as far as it used to.
A simple hook up too. Just connect the red wire to your battery, (just tuck the old plug aside or snip the wires) and your done. I also connected the ground wire as it was right there (even though it is grounded through the chassis.
Mine is rated for 100 amps and I use an Optima Yellow Top. I never have a problem with low charge rates.
A simple hook up too. Just connect the red wire to your battery, (just tuck the old plug aside or snip the wires) and your done. I also connected the ground wire as it was right there (even though it is grounded through the chassis.
Mine is rated for 100 amps and I use an Optima Yellow Top. I never have a problem with low charge rates.
The reason your amp meter don't work is because it's in series with one of the sense wires to the regulator, so it's not used at all in your case....useless....replace with a voltmeter outta some other car....I used a VM from a '80's chebby pickup, bolt in swap....even looks good....
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
I"m sorry, BUT, I HAD my fill of 3X alternators in the 3 years I had my '87 Vette, that damn CS130 sucked.....course this was 12 years ago, and maybe they have improved on them, but maybe NOT, so for MY porposise I put on a SI17 comes off a '79 Seville with rear window defogger....supposed 108 amp rating....same wiring slightly larger diameter...it works.....I run Camaro headlights/a-c/driving lights/TPI, C4 blower, 850 idle speed (computer), and never runs outta juice even with the Dual Spals cranked up via relay controller--full drain....now I do have to admit exchanging the alt with AZone 2x to get a good one, but this last one has been on the car 2+ years now....
Last edited by I'm Batman; May 17, 2007 at 01:09 PM.
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
I run a 1-wire alt and have had good luck with it. I think the reason is that I have most of the major amp junkies on my car wired with relays; they don't pull power from under the dash but instead pull from the starter power wire. This way I am drawing from the main wire that the alt is sensing the voltage. My dash meter still works and actually shows more voltage than before.
Neal
Neal
Veteran
Joined: Oct 2005
Posts: 1,284
Likes: 81
From: Nashville, TN
Yes, My powermaster can be hooked up either way. I have mine hooked up stock and then I ran a 4 gauge power wire back to the pos post on the battery, also ran a ground wire off the alt housing to the frame. Solved all my electrical problems.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,353
From: Santa Ana CA
The reason your amp meter don't work is because it's in series with one of the sense wires to the regulator, so it's not used at all in your case....useless....replace with a voltmeter outta some other car....I used a VM from a '80's chebby pickup, bolt in swap....even looks good....
I didn't say it didn't work, I just said it doesn't seem to swing quite as far as it used to.
The amps gauge on a '64 reads the difference between the voltage at the horn relay and starter motor. The alternator sensor wire has nothing to do with this. If the amps gauge were hooked up to the sensor wire (that is now totally out of the circuit), it wouldn't work at all.
Maybe it doesn't swing quite as far because the new 100-amp alternator does a better job of keeping the battery charged than the old 42-amp unit through the external regulator did, and it charges faster so the gauge swing to the right doesn't last as long.
Because the battery is kept at a higher state of charge, it needs less charging and the amp gauge simply reflects this.