Alternator type

[NashBronco]

Can someone identify this alternator? I am working on a painless install and want to make sure that I wire it up correctly. The wire circled in yellow was not attached to anything prior, just hanging loose. Everything seemed to be working ok though.

 

[DirtDonk]

Looks like a stock type. That would be a 1G small-case version with an output of between 45 and 65 amps depending on model.
The wiring is changed from original, and is missing it's original "strain relief" which was a big molded rubber looking thingy with all the wires encased inside and just little bits sticking out long enough to connect to the alternator.

The wire you circled looks like a ground wire, but also possibly a power wire. And it looks from the picture like it's connected to one of the studs on the back of the alt. Is it just sitting their touching the alternator case?

Anyway, easy enough to wire in a Bronco.
1. New Painless Black w/yellow charge wire to the BAT terminal. with red insulator.
2. New Painless Orange field wire to the post marked FLD with a black insulator I think? Or is it the white one in the pic? I think that's the stator (STA) post, but you can confirm when you remove the alternator.
3. New Painless White w/black stator wire to the STA terminal.
4. New Black wire from one of the GRD studs on the back of the alternator run over to the mounting screw of the voltage regulator. Might come in the kit, or you might have to make your own.

Paul

 

[NashBronco]

thanks Paul. You are correct, the wire I circled is connected to the back of the alternator. Its the other end of it that was just left unconnected. I assume that it must be a ground? Maybe the alternator is getting enough ground through the engine block so it didn't impact anything. Regardless, i will reconnect it.

 

[DirtDonk]

The alternator does get it's main grounding through the case to the engine. The additional ground wire that the factory provides is, from what I understand, so that the alternator AND the regulator both have the same ground potential.
So if that wire is indeed connected to one of the ground lugs on the alternator, and there are no others wrapped up inside the harness, then yes it should be attached to one of the two screws fastening the regulator to the body.

Paul

 

[Broncobowsher]

Now might be a good time to upgrade the alternator since you are doing all the new wiring. The proper 3G will bolt in place of the original alternator. A lot of people get greedy and go to the big 130A unit. And spend a couple years fighting belt squeal. There is a 90A version that doesn't load the belt as much. '92 Aerostar with a 3.0 V6. Swap out the pulley off the old alternator and it bolts in. The closest thing to a surprise is you need a metric bolt to lock the adjustment in place. Just follow the painless instruction for 3G and you are set.

I did it when the EFI and fuel pump added too much at idle when driving at night with the lights and A/C on. Got my idle performance up and a side benefit is the voltage is much more stable now (watching the voltage display on the EFI).

If the old alternator was enough, the 50-100% more output (and better idle output) will be plenty. 90A has less headaches compared to the 130A when on a v-belt.

 

[NashBronco]

Now might be a good time to upgrade the alternator since you are doing all the new wiring. The proper 3G will bolt in place of the original alternator. A lot of people get greedy and go to the big 130A unit. And spend a couple years fighting belt squeal. There is a 90A version that doesn't load the belt as much. '92 Aerostar with a 3.0 V6. Swap out the pulley off the old alternator and it bolts in. The closest thing to a surprise is you need a metric bolt to lock the adjustment in place. Just follow the painless instruction for 3G and you are set. .

I thought about this but then got confused with all the belt squealing issues that are out there. I got a little scared that I was creating more of a problem by changing. I did the painless because my lights weren’t working, among other things, so I don’t know if my alternator needs more juice or not.

I also have a serpentine kit from Sandman that I plant to install at some point. I may wait until then to do the alternator swap.

 

[Broncobowsher]

If you have an Explorer serpentine, don't get the 3G. Make sure you leave the wires long enough (coil it off to the side) so when you remove the voltage regulator and put the Explorer alternator on you just have to shorten the wire, not splice extra length onto it.

 

[NashBronco]

Anyway, easy enough to wire in a Bronco.
1. New Painless Black w/yellow charge wire to the BAT terminal. with red insulator.
2. New Painless Orange field wire to the post marked FLD with a black insulator I think? Or is it the white one in the pic? I think that's the stator (STA) post, but you can confirm when you remove the alternator.
3. New Painless White w/black stator wire to the STA terminal.
4. New Black wire from one of the GRD studs on the back of the alternator run over to the mounting screw of the voltage regulator. Might come in the kit, or you might have to make your own.

Paul

Paul,

My painless kit doesnt have the white/black stator wire that you mention in #3?? only has the other 3 wires you mention for the alternator section. Also there was nothing connected to the STA post with my old wiring kit. not sure what that means.

 

[DirtDonk]

Yes, the '67 would not have had a stator wire, as those were only used on Broncos from '73 to '77. But the Painless should have had one in it, if it was the Bronco-specific harness.
Is this a Bronco, or generic harness?

Either way, all you need is BAT and FLD and GRD to make things play nice together.
The Black w/yellow wire runs up into the harness and around the cabin, feeding all the goodies before coming back out as the Black wire that charges the battery.
This is the wire that has the Maxi-Fuse (60a I think?) holder and might be Red in this case.

So, three wires to the regulator, three wires to the alternator, and you should be good.
As long as they're the correct wires!
The field and ground wires are the only ones common to both. The regulator gets the S wire from the ignition switch, the regulator gets the A wire from the battery, the alternator and regulator are connected together by the wire between the F and the FLD posts, and the wire between one of the case bolts or GRD studs and one of the screws holding the regulator to the body.

Paul

 

[NashBronco]

Yes, the '67 would not have had a stator wire, as those were only used on Broncos from '73 to '77. But the Painless should have had one in it, if it was the Bronco-specific harness.
Is this a Bronco, or generic harness?


Paul

That's Interesting. Yes, its a bronco specific harness from one of the vendors. Not sure why mine doesn't have that wire. Good thing I dont need it.... at least not now. I do plan on upgrading to the Serp set up from sandman, not sure if i will need it then?

 

[DirtDonk]

Nope. Only if you want to run an electric choke on the stock carburetor.

Paul