Alternator Upgrade Related Questions (was One-Wire Alternator Questions)

[dirtymac]

It is time to replace my 1G 40amp alternator with something more powerful for future plans. I have my eye on some 100+ amp one-wire alternators. I know a lot of people are more behind the 3G upgrade, but I think the one-wire is a better option for me. I wouldn't mind keeping the old harness in place but it is in really bad shape.

I have read through the 3G Conversion page and several threads about the 3G conversions and One-wire conversions. Most seem to pertain to newer EFI motors, whereas I have an older carburetor engine with electric choke. Which leads to my first issue. I'm not sure how I can get the power needed for the electric choke. Based on the diagram's I have found, there should be a wire coming off the alternator that directly feeds the choke. I do not think I can just hook my choke directly to the alternator.

I am planning to do the ammeter/volt meter conversion, but that is a little bit off. In the mean time, is there an easy way to disconnect the ammeter so it is not damaged by the higher output alternator? I'd rather not take the instrument cluster apart (again).

Below are some of the threads I have read through:

https://forum.garysgaragemahal.com/One-wire-alternator-tp112799.html

https://forum.garysgaragemahal.com/Help-On-3G-Page-tp86569.html

https://forum.garysgaragemahal.com/GM-one-wire-alternator-tp65069.html

[Gary Lewis]

Your carb's choke needs power from the stator winding of the alternator, which is a half-wave rectified DC. My limited understanding of 1-wire alternators is that they are based on a GM unit, and I don't know if they provide that output. However Ford's 1G, 2G, and 3G alternators do.

Back to the 1-wire, if you are thinking about a Powermaster then I'm not your guy. I wouldn't run one if you gave it to me, for two reasons:

1. You cannot buy parts for them. Instead you have to send them back for repair when they fail.

2. When they fail, and they will, you can't go to a salvage or a parts store and get one off the shelf. You are stranded until you get a replacement.

Instead I'll run something I can replace easily or get parts for when it fails. And that's a 1G or 3G alternator.

As for the ammeter, you could disconnect it. But my worry is more with the shunt than the meter. The shunt is probably sized to handle a max of 60 or 70 amps, which is all the alternators of the day would put out. But if you put an alternator on that has a lot more capacity you could burn the shunt up, depending on how you wire it.

If you leave the wiring stock then you'll be trying to charge the battery through the shunt. And if your battery should get low, when you start the truck the alternator will kick in hard and give you all it has, which could burn up the shunt.

Instead you need to wire the output of the alternator as shown below. Don't use the factory BK/O wire that goes up to S202 as that feeds through the shunt to the battery. Instead wire the alternator's output to the battery's positive side on the starter relay. That way the alternator's output doesn't go through the shunt and you won't burn it up.

And, having done that you won't hurt the ammeter either since the only current it'll be measuring is that going into the cab, which isn't enough to hurt anything - if you haven't installed a killer sound system.

[ArdWrknTrk]

Unplug connector 610.

Bring wire 37 (Y) from S101 to the battery + stud of the fender mounted starter relay.

Bring the fused output of your 1-wire alt to the battery + stud of the fender mounted starter relay.

Toss everything shown below.

The problem with 1 wire alternators is that they are self-exciting, so no matter how high their ultimate output is they provide useless output at idle and low rpms.

[ArdWrknTrk]

Your carb's choke needs power from the stator winding of the alternator, which is a half-wave rectified DC. My limited understanding of 1-wire alternators is that they are based on a GM unit, and I don't know if they provide that output. However Ford's 1G, 2G, and 3G alternators do.

Back to the 1-wire, if you are thinking about a Powermaster then I'm not your guy. I wouldn't run one if you gave it to me, for two reasons:

1. You cannot buy parts for them. Instead you have to send them back for repair when they fail.

2. When they fail, and they will, you can't go to a salvage or a parts store and get one off the shelf. You are stranded until you get a replacement.

Instead I'll run something I can replace easily or get parts for when it fails. And that's a 1G or 3G alternator.

As for the ammeter, you could disconnect it. But my worry is more with the shunt than the meter. The shunt is probably sized to handle a max of 60 or 70 amps, which is all the alternators of the day would put out. But if you put an alternator on that has a lot more capacity you could burn the shunt up, depending on how you wire it.

If you leave the wiring stock then you'll be trying to charge the battery through the shunt. And if your battery should get low, when you start the truck the alternator will kick in hard and give you all it has, which could burn up the shunt.

Instead you need to wire the output of the alternator as shown below. Don't use the factory BK/O wire that goes up to S202 as that feeds through the shunt to the battery. Instead wire the alternator's output to the battery's positive side on the starter relay. That way the alternator's output doesn't go through the shunt and you won't burn it up.

And, having done that you won't hurt the ammeter either since the only current it'll be measuring is that going into the cab, which isn't enough to hurt anything - if you haven't installed a killer sound system.

Gary you need a Megafuse or fuselink in the blue 'new charge cable' shown.

The ammeter is worthless.

If converted to a RCCI voltmeter then state as such and feed from the LG/R key on power and ground the other side of the new/converted instrument.

[Gary Lewis]

Gary you need a Megafuse or fuselink in the blue 'new charge cable' shown.

The ammeter is worthless.

If converted to a RCCI voltmeter then state as such and feed from the LG/R key on power and ground the other side of the new/converted instrument.

I'm beginning to think that we need to have three or four different scenarios. Something like:

• Quick & Dirty: This would be for those that want a 3G but don't want to do any other work. So it'd be pretty much as I said, meaning take the alternator output to the starter relay. Then we'd list the advantages and disadvantages. One disadvantage would be that there's no protection, meaning no megafuse, and your truck could burn down. Some would argue that Ford didn't put one on the 1G or 2G trucks, but the counter would be that they did when they went to the 3G. Another disadvantage would be that the ammeter would only show discharge, so would be worthless. But an advantage would be that everything would be there in case you wanted to go back with a 1 or 2G, like you put in a 1-wire and got stranded in the back of beyond.

• Bare Minimum: As above with a megafuse.

• Cleaned Up: As you described with all of the extraneous stuff removed. But you'd still have an ammeter that was worthless as now it'll never move. But a disadvantage is that you then can't easily go back to a 1 or 2G.

• Done Right: This is the one we've been describing for years, with a megafuse, voltmeter, etc. The advantage over Cleaned Up is that you can tell that the alternator is working because of the voltmeter. But a disadvantage is that you've now altered the wiring so going back would be difficult.

Maybe we don't need Quick & Dirty and just go with Bare Minimum as we can't recommend doing it w/o a fuse. But I wanted to get that out there in light of your comment.

If we had three or four options, with schematics and advantages/disadvantages, then we would be able to answer the questions we get of "but why can't we" do this or that. We'd have thought through solutions that take into account "this or that", at least for the most part. And then people could chose their poison.

Oh yes, about the "why not a 1-wire". I don't see enough of an advantage of a 1-wire over a 3G to make it worth doing, so don't want to go to the trouble of drawing up the schematic or doing the writeup. So maybe I write up my thoughts and bounce it around on here to get something we can agree on and put it on the site. Then if people ask we can point to that and be done. Am I wrong, folks?

 

[ArdWrknTrk]

I'm beginning to think that we need to have three or four different scenarios. Something like:

• Quick & Dirty: This would be for those that want a 3G but don't want to do any other work. So it'd be pretty much as I said, meaning take the alternator output to the starter relay. Then we'd list the advantages and disadvantages. One disadvantage would be that there's no protection, meaning no megafuse, and your truck could burn down. Some would argue that Ford didn't put one on the 1G or 2G trucks, but the counter would be that they did when they went to the 3G. Another disadvantage would be that the ammeter would only show discharge, so would be worthless. But an advantage would be that everything would be there in case you wanted to go back with a 1 or 2G, like you put in a 1-wire and got stranded in the back of beyond.

• Bare Minimum: As above with a megafuse.

• Cleaned Up: As you described with all of the extraneous stuff removed. But you'd still have an ammeter that was worthless as now it'll never move. But a disadvantage is that you then can't easily go back to a 1 or 2G.

• Done Right: This is the one we've been describing for years, with a megafuse, voltmeter, etc. The advantage over Cleaned Up is that you can tell that the alternator is working because of the voltmeter. But a disadvantage is that you've now altered the wiring so going back would be difficult.

Maybe we don't need Quick & Dirty and just go with Bare Minimum as we can't recommend doing it w/o a fuse. But I wanted to get that out there in light of your comment.

If we had three or four options, with schematics and advantages/disadvantages, then we would be able to answer the questions we get of "but why can't we" do this or that. We'd have thought through solutions that take into account "this or that", at least for the most part. And then people could chose their poison.

Oh yes, about the "why not a 1-wire". I don't see enough of an advantage of a 1-wire over a 3G to make it worth doing, so don't want to go to the trouble of drawing up the schematic or doing the writeup. So maybe I write up my thoughts and bounce it around on here to get something we can agree on and put it on the site. Then if people ask we can point to that and be done. Am I wrong, folks?

I'm going to have to get back to this.

I'm trying to keep up with the mail and get parts + a shop lined up right now.

[Gary Lewis]

I'm going to have to get back to this.

I'm trying to keep up with the mail and get parts + a shop lined up right now.

Don't think there's a hurry as we are just talking about how and what to recommend in the future. And this thread is probably not the best place to do it anyway.

I'll start a new thread and ask for opinions.

[Gary Lewis]

Don't think there's a hurry as we are just talking about how and what to recommend in the future. And this thread is probably not the best place to do it anyway.

I'll start a new thread and ask for opinions.

The new thread is here: https://forum.garysgaragemahal.com/Rethinking-The-3G-Conversion-Pages-Process-td144886.html

[dirtymac]

Unplug connector 610.

Bring wire 37 (Y) from S101 to the battery + stud of the fender mounted starter relay.

Bring the fused output of your 1-wire alt to the battery + stud of the fender mounted starter relay.

Toss everything shown below.

The problem with 1 wire alternators is that they are self-exciting, so no matter how high their ultimate output is they provide useless output at idle and low rpms.

I think I need more information about the last line of your reply. Useless at idle and low rpm? Since this is a work-in-progress truck, and since I live in a high-traffic area, the truck tends to idle a lot. Can you tell me more about what you mean?

[dirtymac]

Your carb's choke needs power from the stator winding of the alternator, which is a half-wave rectified DC. My limited understanding of 1-wire alternators is that they are based on a GM unit, and I don't know if they provide that output. However Ford's 1G, 2G, and 3G alternators do.

Back to the 1-wire, if you are thinking about a Powermaster then I'm not your guy. I wouldn't run one if you gave it to me, for two reasons:

1. You cannot buy parts for them. Instead you have to send them back for repair when they fail.

2. When they fail, and they will, you can't go to a salvage or a parts store and get one off the shelf. You are stranded until you get a replacement.

Instead I'll run something I can replace easily or get parts for when it fails. And that's a 1G or 3G alternator.

As for the ammeter, you could disconnect it. But my worry is more with the shunt than the meter. The shunt is probably sized to handle a max of 60 or 70 amps, which is all the alternators of the day would put out. But if you put an alternator on that has a lot more capacity you could burn the shunt up, depending on how you wire it.

If you leave the wiring stock then you'll be trying to charge the battery through the shunt. And if your battery should get low, when you start the truck the alternator will kick in hard and give you all it has, which could burn up the shunt.

Instead you need to wire the output of the alternator as shown below. Don't use the factory BK/O wire that goes up to S202 as that feeds through the shunt to the battery. Instead wire the alternator's output to the battery's positive side on the starter relay. That way the alternator's output doesn't go through the shunt and you won't burn it up.

And, having done that you won't hurt the ammeter either since the only current it'll be measuring is that going into the cab, which isn't enough to hurt anything - if you haven't installed a killer sound system.

I'm still trying to digest all of this so bare with me.

It sounds like I can feed the electric choke from a 3G alternator. It also sounds like I can connect it up to the starter relay (with a megafuse) the same way I would a one-wire alternator. That leaves the entire harness out of the picture and makes it removable, right?

I still have to deal with the ammeter-to-volt meter conversion. I actually have two functioning ammeters and I am shipping one off today for the RCC conversion.

My existing wiring is all in bad shape, so losing that entire harness would be a benefit for me. I also have no plans of going back to a 1G or 2G. However, having an alternator that I can easily swap or work on, is a plus.