Big Brother is going 3G

[Gary Lewis]

Jeff - I'm not sure where those curves come from

This graph is part of a 2019 Motor Trend article.

I would trust Ford documentation and that of DB Electrical before trusting something in a magazine. I can't say Ford and DB Electrical are right, but I'd bet on it.

In any event, regardless of which # you believe, if Big Bro is idling with the lights and heater on you'll be very close to not having enough current from the alternator to keep the voltage up with a 1G. But you'll have more than enough with either of the stock 3G's.

[ArdWrknTrk]

I would trust Ford documentation and that of DB Electrical before trusting something in a magazine. I can't say Ford and DB Electrical are right, but I'd bet on it.

In any event, regardless of which # you believe, if Big Bro is idling with the lights and heater on you'll be very close to not having enough current from the alternator to keep the voltage up with a 1G. But you'll have more than enough with either of the stock 3G's.

∆∆∆ What he said, x100!!!

[BigBrother-84]

In any event, regardless of which # you believe, if Big Bro is idling with the lights and heater on you'll be very close to not having enough current from the alternator to keep the voltage up with a 1G.

Yep, the fan lowers and the lights dim a little, when idling in cold winter time.

Gentlemen, I need some input to choose a right an reliable model from a renowned manufacturer.

As well as for a V-belt pulley model.

There are so much choices and brands out there!

This 1G is running since 80’s and the last thing I want is to replace it with something that will not last.

As I already said, not looking for a bargain, willing to pay the fair value for a solid product.

BTW, not looking neither for a chrome $ look.

I understand that the 95A (7”) is the recommended one in my case.

Go for it.

But to be frank (just curious), I don’t understand why a 130A could not fit. There’s plenty space, the top would be bolted a the same place: Why the lower “arched” bracket could not change angle and accommodate it? Or maybe a different tensioner could do the job?

In other words, why going from 7” to 8” seems difficult, maybe some other wider dimensions I don’t understand?

[Gary Lewis]

In any event, regardless of which # you believe, if Big Bro is idling with the lights and heater on you'll be very close to not having enough current from the alternator to keep the voltage up with a 1G.

Yep, the fan lowers and the lights dim a little, when idling in cold winter time.

Gentlemen, I need some input to choose a right an reliable model from a renowned manufacturer.

As well as for a V-belt pulley model.

There are so much choices and brands out there!

This 1G is running since 80’s and the last thing I want is to replace it with something that will not last.

As I already said, not looking for a bargain, willing to pay the fair value for a solid product.

BTW, not looking neither for a chrome $ look.

I understand that the 95A (7”) is the recommended one in my case.

Go for it.

But to be frank (just curious), I don’t understand why a 130A could not fit. There’s plenty space, the top would be bolted a the same place: Why the lower “arched” bracket could not change angle and accommodate it? Or maybe a different tensioner could do the job?

In other words, why going from 7” to 8” seems difficult, maybe some other wider dimensions I don’t understand?

Jim knows more about this than I do, but I'll respond anyway.

Don't worry about the pulley. Whatever pulley it comes with you'll take off and put your pulley on in its place. So just concentrate on the alternator.

And the 130A unit will work. So if that's what you want go for it.

As for a brand, Jim has had good luck with DB Electrical. John/Machspeed, whom you met, had bad luck with them. I'd still buy from them, but you could go down to your local parts store and buy one of theirs as that would give you someone to deal with later without shipping if you have problems. And if you get one with a lifetime warranty you should be golden.

That's one of the beauties of going with a stock 3G instead of some fancy one-wire alternator. They are available everywhere and if one fails while on the road about any parts store can get you a replacement quickly.

[ArdWrknTrk]

In any event, regardless of which # you believe, if Big Bro is idling with the lights and heater on you'll be very close to not having enough current from the alternator to keep the voltage up with a 1G.

Yep, the fan lowers and the lights dim a little, when idling in cold winter time.

Gentlemen, I need some input to choose a right an reliable model from a renowned manufacturer.

As well as for a V-belt pulley model.

There are so much choices and brands out there!

This 1G is running since 80’s and the last thing I want is to replace it with something that will not last.

As I already said, not looking for a bargain, willing to pay the fair value for a solid product.

BTW, not looking neither for a chrome $ look.

I understand that the 95A (7”) is the recommended one in my case.

Go for it.

But to be frank (just curious), I don’t understand why a 130A could not fit. There’s plenty space, the top would be bolted a the same place: Why the lower “arched” bracket could not change angle and accommodate it? Or maybe a different tensioner could do the job?

In other words, why going from 7” to 8” seems difficult, maybe some other wider dimensions I don’t understand?

The bigger body of the 130A limits your adjustability if you use the short 7" pivot.

You can try it.

It MIGHT work on a Windsor.

I can assure you that you don't want to use a 7" 130A on a 385 V-belt engine.

There never was a 3G with a V-belt, but ALL alternator shafts are 17mm, so the pulley swaps across.

Be mindful that depending on the pulley and the 3G you might need a shim washer behind the already short pulley.

Here, 5/8 washers are a sloppy fit, enough that our 16mm equivalent (5/8") will fit fine over a 17mm shaft.

Any more questions?

[85lebaront2]

Jim knows more about this than I do, but I'll respond anyway.

Don't worry about the pulley. Whatever pulley it comes with you'll take off and put your pulley on in its place. So just concentrate on the alternator.

And the 130A unit will work. So if that's what you want go for it.

As for a brand, Jim has had good luck with DB Electrical. John/Machspeed, whom you met, had bad luck with them. I'd still buy from them, but you could go down to your local parts store and buy one of theirs as that would give you someone to deal with later without shipping if you have problems. And if you get one with a lifetime warranty you should be golden.

That's one of the beauties of going with a stock 3G instead of some fancy one-wire alternator. They are available everywhere and if one fails while on the road about any parts store can get you a replacement quickly.

The 130 amp can be found on Taurii with the 3.8L V6 that is a pretty good fit on our trucks. If you are getting one from a junkyard that allows you to pull your own parts, get as much of the alternator harness as you can.

[ArdWrknTrk]

The 130 amp can be found on Taurii with the 3.8L V6 that is a pretty good fit on our trucks. If you are getting one from a junkyard that allows you to pull your own parts, get as much of the alternator harness as you can.

The 3.8 has the 8.25" C-C

The 3.0 is 7"....

[BigBrother-84]

Jeff - You shouldn't combine what we discussed in the Rethinking The 3G Conversion Pages/Process thread and what's on the 3G Conversion page. The thread is, as its title says, a rethink of how to wire a 3G. The 3G Conversion page is old-think.

The reason for the relay was because I wanted to know the actual battery voltage rather than the voltage in the cab - and those are two different things. So I wanted the voltmeter to be connected to the circuitry as close to the battery as is possible, and that required a relay to turn power off to the volt meter when the key was off.

But the new-think is that people don't really care exactly what the voltage is, so tap into a source of switched power because then you won't need the relay. (After all, there are no numbers on the Rocketman voltmeters, so they cannot be terribly accurate.)

Given that we decided to wire it as shown below, and the LG/R wire comes from the ignition switch and provides both power to the alternator to bootstrap it in but also to the voltmeter. In other words, no relay is needed.

Gary — About the harness.

I took couple of minutes to examine it. I jumped back to the Rethinking The 3G Conversion Pages/Process thread, and trying to figure out where each terminal has to be plugged.

Need some light.

Here is a diagram of the harness. My questions in purple:

• The alternator plug (just curious ), which wires (gray, yellow) are connected together?

• Where to connect the choke heater?

• About the Voltmeter connection (sorry, you'll feel as repeating, I apologize)?

• The two yellow wires are to connect where?

Thanks!

[Gary Lewis]

Gary — About the harness.

I took couple of minutes to examine it. I jumped back to the Rethinking The 3G Conversion Pages/Process thread, and trying to figure out where each terminal has to be plugged.

Need some light.

Here is a diagram of the harness. My questions in purple:

• The alternator plug (just curious ), which wires (gray, yellow) are connected together?

• Where to connect the choke heater?

• About the Voltmeter connection (sorry, you'll feel as repeating, I apologize)?

• The two yellow wires are to connect where?

Thanks!

Jeff - This is the key schematic. It shows how you are to use the harness I sent.

But let me try to address your questions as I understand them:

• Voltmeter: You don't do anything but change out the ammeter for the voltmeter. The C610 connector in the harness I sent is wired to send key-on power to your voltmeter on one side and ground the other side.

• Choke Heater: Your Wh/Bk wire connects to the stator terminal on the new 3G.

• Y/LG: This wire has an eyelet on it and it'll go to a screw on the fender to serve as ground.

• Y/Wh: This wire should also have an eyelet on it and it goes to the same terminal on the megafuse holder that the Bk/O wire goes to.

Does that answer your questions?

[BigBrother-84]

Jeff - This is the key schematic. It shows how you are to use the harness I sent.

But let me try to address your questions as I understand them:

• Voltmeter: You don't do anything but change out the ammeter for the voltmeter. The C610 connector in the harness I sent is wired to send key-on power to your voltmeter on one side and ground the other side.

• Choke Heater: Your Wh/Bk wire connects to the stator terminal on the new 3G.

• Y/LG: This wire has an eyelet on it and it'll go to a screw on the fender to serve as ground.

• Y/Wh: This wire should also have an eyelet on it and it goes to the same terminal on the megafuse holder that the Bk/O wire goes to.

Does that answer your questions?

I continue my investigations, preparing for future 3G swap.

After job, I went to Big Bro's garage and looked under the hood to identify the different places where the new harness will plug.

Friends, I'm probably blind, but I do not see the C610 connector. Where should I look?

As Jim pointed here, seems that there is couple of possibilities...