The Stovebolt Site Forums The Shop Area The Electrical Bay gen. to alt.

hi guys. how do i change the wiring on voltage reg.
changing from a gen. to a alt. and what is that plug
in the alt. that says fuel?

If you use a 1-wire alternator you can eliminate the voltage regulator. There's an internal regulator in the alternator. You will need a "DA Plug". Patrick's has em.

There should be three cables running to your voltage regulator. You can just splice these all together.

The DA Plug should have a long yellow wire and a short red wire coming out of it. The red wire gets connected to the post on the alternator, and the yellow wire should go to the key switch. Without this, turning the key off won't shut off the engine.

Use a 1-wire alternator if possible. It will start charging at lower RPMs.

thanks
i have the alt. already, it has a pos. and neg and the plug
in the middle for fuel help????

I think the wire should go to one side of the ammeter - the other side of the ammeter connects to the ignition switch...

Someone else will chime in shortly.

http://www.powermastermotorsports.com/faq-alternators.html#15 I do not remember where I found this photo but it works (even if the author's spelling is weak).

Wiring a one-wire alternator.

Thanks Tim! I forgot how the wires went... You saved the day - again.

thanks to all,i still don't get it, what about the fuel
hookup on alt.do i ignore the positive connection on
the alt? as you can tell i'm new to this,even though
i'm old

Oof - I was thinking one wire and I think Tim was, too. I'm currently searching for the info. you need...

I found the diagram. click here ...I think it's for a system with an indicator light only - please read this topic.

Herme,


Your alternator is a SI unit. It has a large BATT lug that you should connect to the old BATT wire that went on the old voltage regulator. The two other wires can be taped up and stowed away..they aren't used.

The DA plug goes into a receptacle that has tabs marked 1 and 2. The wire that comes from terminal #1 must powered whenever the engine is turned on.

The wire from #2 can wrap around and be connected to the large BATT lug. Because this is now a 12 volt system, there are other things that need to be done, like 12 headlights, bulbs, battery and coil. A small inexpensive voltage reducer in the power wire to the fuel gauge will take care of that.

Does this make sense...I hope so.

Stuart

Herme

I coverted my truck from gen to alt recently. I bought the 80 amp alt from Patricks. It comes with DA plug. One wire (red) from plug to goes to stud on the back of the alt and the yellow wire you can connect to the S side of the starter selenoid. There is bump in the DA plug which cuts of the electricity to your starter and turns of the engine when you turn off the key. Battery is charging and running normal

My 2 Cents

Ganesh

Stuart
thank you i have a 54 chevy pickup already changed over
to 12 volt. i bought a plug for the alt that has a blue wire
and a black wire. ?????

Herme,

I'm not sure on the wire colors. The alternator case should have the numbers 1 and 2 cast into it under each tab (DA plug). The plug only goes in one way and the wire for #1 is smaller than the wire for #2.

The smaller wire (#1) will attach to any switched source of power, like the key switch. The larger wire can have a terminal crimped onto it and attach to the big BATT lug.

If you can't find any markings on the case, the #1 wire/terminal is the one nearest to the large BATT lug.

Because the truck has already be swapped to 12 volt, it was probably run that way for awhile and everthing should be OK, fuel gauge included. If you have any doubts, come on back and ask more questions. Good luck.

Stuart

stuart--- have new alt. and reg.all hooked up. still won't
charge,the ampmeter stays the same unless you turn on the lights.
this alt. is not the one wire type.any ideas?

Herme,

Probably not very good ones! The alternator has only three wires. The big wire from the BATT lug should be spliced into the large wire where the voltage regulator was situated. That large wire was attached to BATT on the voltage regulator and should terminate at your ammeter.

The DA plug has the remaining two wires...the wire plugged into the tab above #2 (on the right, looking from the back of the alternator) should go to the large BATT lug. The other small wire above tab #1 has to see 12 volts whenever you turn the key on. If you have a meter, you can check this pretty easily.

My guess is that #1 isn't being powered when the key is ON.

There should have been three wires at the site of the old voltage regulator. A BATT wire, a ARM (gen) wire and a FIELD (F) wire. The ARM and FIELD get wrapped up and stuffed away, but the BATT wire needs to hook to your big wire from the alternator.

I don't know that you ever told us what kind of rig you have. The alternator I am describing is called a SI unit and its little DA plug is on its periphery, not on the back. There is a alternator with a DA plug on the back, but this is a whole different ball-o-wax.

This is a simple wiring deal, I'm sure you just have something in the wrong spot...keep us posted.

hi stuart, this alt has the plug on the back.
what to do?

Another article here .

Herme,

There is a great picture of a SI alternator in the link 54TOW posted (thanks). Sometimes it's difficult to differentiate between 'plug on the back' and 'plug around the circumference'. The picture of the SI alternator explains it all.

If you don't have the SI Delco alternator, and you do have the old 10DN with the plug on the back, my only advice would be to trade it in for a SI unit...you don't want to go through a bunch of work and end up with a external voltage regulator.

Take a look at the picture in the link and see if it's what you have.

I have enclosed another link showing the different positioning of the DA terminals, which is the dead nuts method of ID'ing them.

http://www.rowand.net/Shop/Tech/GmAlternatorIdentification.htm

Stuart