Converting from externally regulated alternator to one wire setup - question
12-07-2015, 05:39 PM
#1
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Converting from externally regulated alternator to one wire setup - question
My regulator is going bad and sometimes, it causes the alternator to not charge at all. I have a old one wire alternator that I had in my race car before I took it off as I was drag racing it without alternator.. It was working perfectly fine when I took it off a few years ago.. I installed the one wire alternator and hooked up the red power wire to the power terminal, the ground wire to the ground terminal and left the 2 wires from the regulator off.. Started the car.. and it won't charge? What do I need to do to go to a one wire alternator?
I ended up disconnecting both wires from the alternator and started the car. I used a voltmeter to check the voltage and the alternator did not produce any power with the car running. Is the alternator bad or do I need to change anything to make it work?? I thought that a one wire alternator is supposed to produce about 14 volts when it's turning.. Am I missing anything or did my alternator go bad while it was sitting in the garage for a few years?
I ended up disconnecting both wires from the alternator and started the car. I used a voltmeter to check the voltage and the alternator did not produce any power with the car running. Is the alternator bad or do I need to change anything to make it work?? I thought that a one wire alternator is supposed to produce about 14 volts when it's turning.. Am I missing anything or did my alternator go bad while it was sitting in the garage for a few years?
Last edited by GrandSportC3; 12-07-2015 at 05:41 PM.
12-07-2015, 05:53 PM
#2
Melting Slicks
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My regulator is going bad and sometimes, it causes the alternator to not charge at all. I have a old one wire alternator that I had in my race car before I took it off as I was drag racing it without alternator.. It was working perfectly fine when I took it off a few years ago.. I installed the one wire alternator and hooked up the red power wire to the power terminal, the ground wire to the ground terminal and left the 2 wires from the regulator off.. Started the car.. and it won't charge? What do I need to do to go to a one wire alternator?
I ended up disconnecting both wires from the alternator and started the car. I used a voltmeter to check the voltage and the alternator did not produce any power with the car running. Is the alternator bad or do I need to change anything to make it work?? I thought that a one wire alternator is supposed to produce about 14 volts when it's turning.. Am I missing anything or did my alternator go bad while it was sitting in the garage for a few years?
I ended up disconnecting both wires from the alternator and started the car. I used a voltmeter to check the voltage and the alternator did not produce any power with the car running. Is the alternator bad or do I need to change anything to make it work?? I thought that a one wire alternator is supposed to produce about 14 volts when it's turning.. Am I missing anything or did my alternator go bad while it was sitting in the garage for a few years?
The single wire alternators use a special single wire voltage regulator but its possible the rotor has lost it's magnetism after sitting so long. Try momentarily connecting a jumper wire from the HOT post to the #1 terminal and see if it'll energize it. If not connect a permanent wire from the HOT post to the #2 terminal.
The OEM alternator: The #1 terminal single strand energizing wire often breaks inside the plugin which will cause it to charge on-and-off like you were describing. So you could try replacing that plugin (about $5 and found in the "Help Us" section of your auto parts store. The new plugin comes with 8" leads so all you have to do is splice it onto your existing wires; using two butt connectors.
Last edited by toobroketoretire; 12-07-2015 at 05:58 PM.
12-07-2015, 05:57 PM
#3
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You still need a HOT wire going to the #2 terminal and you can easily run a jumper wire from your output post to that #2 terminal.
The OEM alternator: The #1 terminal single strand energizing wire often breaks inside the plugin which will cause it to charge on-and-off like you were describing. So you could try replacing that plugin (about $5 and found in the "Help Us" section of your auto parts store. The new plugin comes with 8" leads so all you have to do is splice it onto your existing wires; using two butt connectors.
The OEM alternator: The #1 terminal single strand energizing wire often breaks inside the plugin which will cause it to charge on-and-off like you were describing. So you could try replacing that plugin (about $5 and found in the "Help Us" section of your auto parts store. The new plugin comes with 8" leads so all you have to do is splice it onto your existing wires; using two butt connectors.
12-07-2015, 05:57 PM
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Assuming it's a 10SI alternator, jumper power for a second or two to terminal #1 while the engine is running. The alternator should start charging. If it doesn't, then it is bad or not the 1-wire you believe it is.
Once you do the jumper the first time, it should start charging the next time you start the engine. But don't be surprised if you have to rev the engine to 2000+ rpm before it starts charging.
Once you do the jumper the first time, it should start charging the next time you start the engine. But don't be surprised if you have to rev the engine to 2000+ rpm before it starts charging.
12-07-2015, 05:59 PM
#5
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I BET your alt. is fine what you need do is looking from the back I ASSume your two bladed regulator has the blades aligned -- and not || but that depends on the year of your car, an external regulator mounted typically on the firewall or like my '72 a built in to the alt.
SO ASSuming it's the later version...looking from the rear at the two connections the MOST clockwise should be always hot...same as the output stud, with engine off.....
the lease clockwise should be hot with igniton ON and engine running....that is fed through the red light on the dash...it says ALT/BAT/GEN whatever.....lights up if the alt. is not putting out....but that circuit is what triggers the alt to put out....the other one determines the voltage.....
hope this helps....
SO ASSuming it's the later version...looking from the rear at the two connections the MOST clockwise should be always hot...same as the output stud, with engine off.....
the lease clockwise should be hot with igniton ON and engine running....that is fed through the red light on the dash...it says ALT/BAT/GEN whatever.....lights up if the alt. is not putting out....but that circuit is what triggers the alt to put out....the other one determines the voltage.....
hope this helps....
12-07-2015, 06:00 PM
#6
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DO NOT do as suggested and permanently connect the #1 terminal to power. That will just cause a drain that kills your battery.
Now you have 2 other people both telling you how to "fix" the wiring to an internally regulated alternator, which you Do NOT have.....Ignore it and continue with the internally regulated upgrade.
Last edited by lionelhutz; 12-07-2015 at 06:02 PM.
12-07-2015, 10:25 PM
#7
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The single wire alternators use a special single wire voltage regulator but its possible the rotor has lost it's magnetism after sitting so long. Try momentarily connecting a jumper wire from the HOT post to the #1 terminal and see if it'll energize it. If not connect a permanent wire from the HOT post to the #2 terminal.
The OEM alternator: The #1 terminal single strand energizing wire often breaks inside the plugin which will cause it to charge on-and-off like you were describing. So you could try replacing that plugin (about $5 and found in the "Help Us" section of your auto parts store. The new plugin comes with 8" leads so all you have to do is splice it onto your existing wires; using two butt connectors.
The OEM alternator: The #1 terminal single strand energizing wire often breaks inside the plugin which will cause it to charge on-and-off like you were describing. So you could try replacing that plugin (about $5 and found in the "Help Us" section of your auto parts store. The new plugin comes with 8" leads so all you have to do is splice it onto your existing wires; using two butt connectors.
Thanks
12-08-2015, 07:32 AM
#8
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Now do it right,
Connect the wire going to terminal #3 of the regulator to terminal #2 of the new alternator.
Connect the wire going to terminal #4 of the regulator to terminal #1 of the new alternator.
Connect the wire going to terminal #3 of the regulator to terminal #2 of the new alternator.
Connect the wire going to terminal #4 of the regulator to terminal #1 of the new alternator.
12-08-2015, 08:56 AM
#9
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Also, how do I identify the numbers on the regulator terminal? Are there numbers stamped on it? If not, how do I determine what side is terminal one?
Last edited by GrandSportC3; 12-08-2015 at 08:59 AM.
12-08-2015, 09:55 AM
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Terminal #3 on the regulator is the voltage sensing wire that is equivalent to terminal #2 on the internally regulator alternator.
Terminal #4 on the regulator is the light or key-on energizing wire that is equivalent to terminal #1 on the internally regulator alternator.
If you look at the regulator with the terminals on the left side they are numbered top to bottom. The #3 wire should be red and the #4 wire should be brown. The #1 and #2 wires go to the externally regulated alternator plug. White and blue maybe, not positive though since it's been years since I looked at an externally regulated wiring diagram.
Terminal #4 on the regulator is the light or key-on energizing wire that is equivalent to terminal #1 on the internally regulator alternator.
If you look at the regulator with the terminals on the left side they are numbered top to bottom. The #3 wire should be red and the #4 wire should be brown. The #1 and #2 wires go to the externally regulated alternator plug. White and blue maybe, not positive though since it's been years since I looked at an externally regulated wiring diagram.
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12-08-2015, 11:06 AM
#11
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Terminal #3 on the regulator is the voltage sensing wire that is equivalent to terminal #2 on the internally regulator alternator.
Terminal #4 on the regulator is the light or key-on energizing wire that is equivalent to terminal #1 on the internally regulator alternator.
If you look at the regulator with the terminals on the left side they are numbered top to bottom. The #3 wire should be red and the #4 wire should be brown. The #1 and #2 wires go to the externally regulated alternator plug. White and blue maybe, not positive though since it's been years since I looked at an externally regulated wiring diagram.
Terminal #4 on the regulator is the light or key-on energizing wire that is equivalent to terminal #1 on the internally regulator alternator.
If you look at the regulator with the terminals on the left side they are numbered top to bottom. The #3 wire should be red and the #4 wire should be brown. The #1 and #2 wires go to the externally regulated alternator plug. White and blue maybe, not positive though since it's been years since I looked at an externally regulated wiring diagram.
12-08-2015, 02:25 PM
#12
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Terminal #3 on the regulator is the voltage sensing wire that is equivalent to terminal #2 on the internally regulator alternator.
Terminal #4 on the regulator is the light or key-on energizing wire that is equivalent to terminal #1 on the internally regulator alternator.
If you look at the regulator with the terminals on the left side they are numbered top to bottom. The #3 wire should be red and the #4 wire should be brown. The #1 and #2 wires go to the externally regulated alternator plug. White and blue maybe, not positive though since it's been years since I looked at an externally regulated wiring diagram.
Terminal #4 on the regulator is the light or key-on energizing wire that is equivalent to terminal #1 on the internally regulator alternator.
If you look at the regulator with the terminals on the left side they are numbered top to bottom. The #3 wire should be red and the #4 wire should be brown. The #1 and #2 wires go to the externally regulated alternator plug. White and blue maybe, not positive though since it's been years since I looked at an externally regulated wiring diagram.
12-08-2015, 03:32 PM
#13
Melting Slicks
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Now I'm really confused. Is it a 10SI alternator or an original 10DN (external regulator) that has been converted to a single wire hook up? Can you take a picture of it so we can see what you're dealing with? The 10DN has a two terminal plugin on the rear and the 10SI has it on the side.
12-08-2015, 06:25 PM
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On the old front mounted regulator GM's the brown #4 wire was long enough to re-route to the alternator. The red #3 wire just came from the horn relay which was right beside the regulator so the best solution was to either use a new wire or connect one of the original alternator wires between the horn relay and new alternator. I'm not sure how well that would work with the C3 wiring layout.
There are conversion plugs you can use too that do it plug and play.
12-08-2015, 10:30 PM
#16
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you can do it any way that makes sense to you. Some people use the original wires that went to the alternator and just connect them together where the regulator was. Others pull back the harness wrap and re-route and neaten it all up so you wouldn't even know the regulator was removed.
On the old front mounted regulator GM's the brown #4 wire was long enough to re-route to the alternator. The red #3 wire just came from the horn relay which was right beside the regulator so the best solution was to either use a new wire or connect one of the original alternator wires between the horn relay and new alternator. I'm not sure how well that would work with the C3 wiring layout.
There are conversion plugs you can use too that do it plug and play.
On the old front mounted regulator GM's the brown #4 wire was long enough to re-route to the alternator. The red #3 wire just came from the horn relay which was right beside the regulator so the best solution was to either use a new wire or connect one of the original alternator wires between the horn relay and new alternator. I'm not sure how well that would work with the C3 wiring layout.
There are conversion plugs you can use too that do it plug and play.