One Wire Alternator

64Ranger · Post by **64Ranger** » October 11, 2011, 10:54 am

Does anyone have a schematic or a how-to article for hooking up a one wire Alternator to our trucks?

Thanks for any info...

Haus · Post by **Haus** » October 11, 2011, 1:20 pm

You just run the wire to the selenoid. Get to throw all the other wires and regulator in the parts bin.

64Ranger · Post by **64Ranger** » October 12, 2011, 10:12 am

That sounds too easy. Thanks for the info. That makes me feel better.

Gritsngumbo · Post by **Gritsngumbo** » October 12, 2011, 11:08 am

That's why they call it "one wire" :-)

cooter · Post by **cooter** » October 12, 2011, 5:35 pm

wire to the power side of the solenoid not the switched side of the solenoid

azjake · Post by **azjake** » October 12, 2011, 10:32 pm

cooter wrote:wire to the power side of the solenoid not the switched side of the solenoid

Thanks! I was just gonna ask!!!

Jake

okiewelder · Post by **okiewelder** » October 13, 2011, 8:27 am

I have a gm alt on my ford and need to find a smaller one to run.
Does anyone know what year and vehicle to get one for that is a small gm internal regulated one?
Thanks,

64Ranger · Post by **64Ranger** » October 13, 2011, 9:53 am

With a one wire set up and using the stock alternator gauge in the instrument cluster, do you just run that same one wire all the way up to the gauge and through the loop and back to the power side of the solenoid?

Thanks for all the info guys... I guess I am not the only one who is electrically challenged.

bobenhotep · Post by **bobenhotep** » October 13, 2011, 10:07 am

okiewelder wrote:I have a gm alt on my ford and need to find a smaller one to run.
Does anyone know what year and vehicle to get one for that is a small gm internal regulated one?
Thanks,

if you are running the big delco, like off of a buick, the small one is easily had by asking for a 63 amp delco. if they ask for year, model, etc, say a 78 camaro.

Haus · Post by **Haus** » October 13, 2011, 10:49 am

I think this is the one I have. They also offer a 60 amp and 140 amp.

http://www.summitracing.com/parts/PWM-8-47101/

I'm running dakota digital guages and an EZ wire wiring harness so I'm not much help on your alt guage question.

rwhistles · Post by **rwhistles** » October 13, 2011, 4:11 pm

this is the one I plan on putting on the new motor for my truck

http://cgi.ebay.com/ebaymotors/Ford-Mus ... 1c1e9493af

had to notch the bracket to get min.adjustment.but looks good on motor to me.

anyone see a problen with it?

Haus · Post by **Haus** » October 13, 2011, 5:27 pm

Remanufactured vs. new.

Truckrat · Post by **Truckrat** » October 13, 2011, 6:10 pm

Doug, you want to run a fairly large wire from the big post on the alt to the battery side of the solenoid.
8 guage is good, but you don't want to run that all the way up under your dash and back out.
TR

Roger Carter · Post by **Roger Carter** » October 13, 2011, 6:25 pm

64Ranger wrote:With a one wire set up and using the stock alternator gauge in the instrument cluster, do you just run that same one wire all the way up to the gauge and through the loop and back to the power side of the solenoid?

Thanks for all the info guys... I guess I am not the only one who is electrically challenged.

On the factory / dealer ammeters for our trucks there is an insulated terminal typically mounted just below the starter solenoid on the inner fender. As I remember it has a single 5/16" stud on it.
All wires connected to the (+) side of the solenoid, with the exception of the battery cable, land on this terminal.
The one wire from your one wire alternator should land on this terminal also.
Now for the two wires from the ammeter. One lands on the (+) side of the starter solenoid, with the battery cable, and the second lands on the insulated terminal, with all the other wires.
If the ammeter reads "backwards" swap the two ammeter wires on the solenoid and terminal.

Wiring the ammeter this way allows the ammeter to show all discharge and charge in the electrical system. All power coming from or going to the battery passes through the ammeter, with the exception of the actual starter draw. It is critical you run a full sized wire for the ammeter leads. I think the factory used a #10 wire. This was adequate for the 40-45 amp alternators our trucks originally had. A #8 would me a minimum, in my opinion, for a 60-65 amp altermator. Remember, the full load of the electrical system runs thgrough this wire.
If you wire it the way you suggested, you will only see the charging side of the system. That is, the ammeter only the current the alternator is putting through the ammeter.

A better, and much safer option would be to install a voltmeter, in place of the ammeter. A voltmeter will show similar information, though in a different format, and you don't have to run the high current wires into the cab thereby reducing the chance for fire.

Hope this helps.

Roger Carter

Mellvis · Post by **Mellvis** » October 14, 2011, 5:49 pm

All of the older internal regulator GM alternators that I have messed with (and my memory is not the best) had a plug with two wires and the "BAT" terminal. What happens to that two-wire plug?

cooter · Post by **cooter** » October 14, 2011, 10:26 pm

on the gm alt, the #1 connector goes to a switched battery source and #2 goes to an unswitched battery source, on a 1 wire the connector is covered

banjopicker66 · Post by **banjopicker66** » October 15, 2011, 8:34 am

Truckrat wrote:... but you don't want to run that all the way up under your dash and back out.
TR

To use the factory ammeter, this is how it has to be done, as mentioned earlier by Roger.
If you do not have the insulated stud, look for a neat GM multi-stud covered setup on mid-90s small trucks (possibly others).
Here is a step by step path to wire in the ammeter:
1. Remove all the wires from the battery side of the solenoid.
2. Reattach the battery cable and one of the 2 ammeter wires to the solenoid.
3. To the insulated stud, attach all the other wires plus the second of the 2 ammeter wires. EDIT -And also the alternator wire needs to be attached here.
4. Test the polarity of the ammeter wires. With the engine off, turn on the headlights. The ammeter should show a discharge to the left, in the negative side of the gauge.
5. If it shows charge instead, you need to reverse the 2 ammeter wires. The easiest way to do this is at the solenoid and the stud instead of at the gauge. Just switch them around - but only the 2 ammeter wires, not all the others.
Finally, any electrical accessories you add should be powered off the insulated stud, not the battery if you want to have the ammeter monitor the draw.
If instead you feel the ammeter wiring is too light duty, or you are adding some heavy wattage accessories such as power inverters, you will probably want to run them directly off the solenoid.
There is a disadvantage to allowing electrical devices to draw juice outside of the ammeter circuit. If you use battery juice that is not going through the ammeter, your system can be draining the battery but you will not be able to discern that fact because the ammeter won't show it.

64Ranger · Post by **64Ranger** » October 18, 2011, 10:34 am

Thank Banjo for the write up. I have one of the gauge clusters from the big trucks that have the alternator gauge in place of the idiot light. There is a loop on the back of the gauge that some wire goes through. There are not two posts on the back of the gauge. That is why I was thinking of running the hot wire from the alternator through the loop to measure the current flow.

Thanks again for all the info guys,

banjopicker66 · Post by **banjopicker66** » October 18, 2011, 11:02 am

Doug, that is a different type of ammeter, and is a lot safer and easier to install than the type I described.
The ones with 2 posts have the full and actual current flowing through the gauge.
Your type still uses the entire current flow, but the current doesn't flow through the gauge, just through the wire. Instead, this type ammeter indicates the current by measuring the magnetic field around the wire as the current flows through it.
It really is nicer, for it means no external connections to short out when working with the instrument panel!
You still have to have the current flowing through the wire in series as I described, but you do not have to connect it physically to the ammeter.
One additional issue is the size of the wire. A wire too large, too small or with too much insulation or a shielding insulation will make the readings inaccurate. Try to use the original size and type if wire if possible.

banjopicker66 · Post by **banjopicker66** » October 18, 2011, 11:13 am

64Ranger wrote:That is why I was thinking of running the hot wire from the alternator through the loop to measure the current flow.

Don't do that. Although that arrangement will measure a charging condition, it cannot show a discharge condition, that is, juice moving from the battery to the truck's circuits, if the alternator quits working, or the draw is greater than it can handle.

If you set it up as I described above, the ammeter will work as it is intended to.
Except, of course, you need only run the one wire through the loop instead of attaching it to the gauge.

Here is how it should look as revised for your situation:
Attach the battery cable and one end of the ammeter wire to the battery side of the solenoid.
Run the ammeter wire into the cab, through the loop, and back out to the insulated stud.
Attach the other end of the ammeter wire, the alternator wire and the truck circuitry wires to the insulated stud.

Also, I just realized an error in the earlier step-bystep post. I left out that the alternator wire needs to be attached to the insulated stud. I edited it to reflect that omission, but it is included in this post.
I am sure sorry about that, and hope it did not cause any confusion.

Hope this helps!

One Wire Alternator

One Wire Alternator

alt

Re: alt