Alternator Help...please

[Shawn Erwin]

Greetings Everyone,

I need help with my alternator. I have no idea what make it is but it is set up for a "one wire" application. I was anticipating a radiator fan upgrade and needed more juice and I had the alternator rebuilt to about 150 amps. Now the issue, at idle, the alternator is only maintaining 12 volts or lower. At driving speed, the system begins to charge all the way up to 13.7 to 14 volts. As you guys know this is a problem when running a dual radiator fan set up at a stop light in the summer with the lights on.

Another interesting thing is that there is another smaller wire running off a an alternator plug to the wiring harness. The female end of the plug has four pins and the wire is coming of the second pin. I have no idea what this wire is for - energizer wire? Everything that I have researched on current aftermarket one wire alternators don't need a separate wire coming going to the harness.

I have attached photos of the alternator, plug, and the small wire coming off of the alternator in hopes that someone can identify it and the purpose of the small wire.

Thanks in advance.

Cheers,
Shawn

[cycleguy55]

This is why I advise people to avoid one-wire alternators: http://www.madelectrical.com/electri...hreewire.shtml

I'm running a 130 amp Ford 3G alternator and it's great.

[Shawn Erwin]

Thanks, does the 3G require a voltage regulator?

[Joey.S]

Originally Posted by Shawn Erwin

Thanks, does the 3G require a voltage regulator?

No regulator is built in.

I have a 3g on my cobra works as it should, I ran the Voltage sense wire (BLUE) to the accessory side of the fuse box. The 3G is available easily at any parts store not to expensive and works great. I have one on my 65 tbird for 14 years 130 amp version no problems what so ever.

BTW if you need the plug for the 3g Standard Motor Products makes the plug for $18.00

Joey.S

[Shawn Erwin]

Thanks Joey. What year and model of car/truck would you ask for at the part store? Mustang or truck? You know how these kids are at the part stores. Very few of them are car people and they have never wrenched on a car before. They only have a computer to look stuff up.

[wrench87]

I have a 3g 95 amp alternator on my 445, I purchased it from pa performance part number 1614E

[Joey.S]

Originally Posted by Shawn Erwin

Thanks Joey. What year and model of car/truck would you ask for at the part store? Mustang or truck? You know how these kids are at the part stores. Very few of them are car people and they have never wrenched on a car before. They only have a computer to look stuff up.

I just ask for a alternator for a 1999 Ford Taurus 3.0L V6 130amp version.

Joey.S

[767Jockey]

I also run a Ford 3G. Works flawlessly.

[cycleguy55]

Originally Posted by Shawn Erwin

Thanks Joey. What year and model of car/truck would you ask for at the part store? Mustang or truck? You know how these kids are at the part stores. Very few of them are car people and they have never wrenched on a car before. They only have a computer to look stuff up.

My 130 amp 3G is from a 1996 Mustang V6. It's actually a junkyard pull, and I grabbed as much of the harness as I could, including the 175 amp mega fuse - though I did need to purchase a holder for it from a local battery & alternator store.

Here are 1G to 3G conversion instructions: https://www.motortrend.com/how-to/in...r-older-fords/

Wiring diagram:

Here's part of what makes 3G alternators so good - higher output that starts at much lower RPM. Also note a 130 amp alternator can go much higher than it's rated output - which is why the matching mega fuse is 175 amps.

[C5GTO]

Originally Posted by Shawn Erwin

Greetings Everyone,

I need help with my alternator. I have no idea what make it is but it is set up for a "one wire" application. I was anticipating a radiator fan upgrade and needed more juice and I had the alternator rebuilt to about 150 amps. Now the issue, at idle, the alternator is only maintaining 12 volts or lower. At driving speed, the system begins to charge all the way up to 13.7 to 14 volts. As you guys know this is a problem when running a dual radiator fan set up at a stop light in the summer with the lights on.

Another interesting thing is that there is another smaller wire running off a an alternator plug to the wiring harness. The female end of the plug has four pins and the wire is coming of the second pin. I have no idea what this wire is for - energizer wire? Everything that I have researched on current aftermarket one wire alternators don't need a separate wire coming going to the harness.

I have attached photos of the alternator, plug, and the small wire coming off of the alternator in hopes that someone can identify it and the purpose of the small wire.

Thanks in advance.

Cheers,
Shawn

I'm not an alternator expert but your alternator looks just like the one in my Cobra. Mine is an GM one wire from an intermediate sized car, I beleive late 90's or early 2000s. 150 amps sounds just about right. My alternator guy built mine for me and clocked the housing so it would work in the Ford configuration. Mine has the slot with 4 pins but these are not used. I really do just have a single wire going the the battery on my setup.

In the 1 wire configuration, the alternator needs to be spun up (about 1,200 engine rpm) before it energized and starts producing power. On mine, once it's producing power, it keeps the system at 14.5 volts even at an engine idle. My car only has a single coolant fan but it does draw about 20 amps. I've also got EFI, so electric fuel pump and all the other electric stuff that goes with it.

If you had someone work on your alternator, I'd take it back and have the test/fix it. If yours is the same as alternator as mine, it's very capable of producing more than enough power for a Cobra.

[Shawn Erwin]

Thanks Joel!

Brian: I don't have a gen light. So, I need to wire a resistor for the ignition switch wire?

[cycleguy55]

Originally Posted by Shawn Erwin

Thanks Joel!

Brian: I don't have a gen light. So, I need to wire a resistor for the ignition switch wire?

No, you can ignore the resister and the idiot light in the above diagram. Your wiring will look like this:


This is one of the images from the linked article.