I have a 95amp 3G alternator mounted, from a F150/Bronco. The wiring threads I've been reading have confused me. Hopefully someone can make this simple for me.

On the internal regulator terminals they are labeled as: A, S, I.

A - gets connected to the terminal that will be connected directly to the battery using an 8 gauge piece of wire, to charge the batt. (yellow line in pic)

S - Gets connected to one of the screws that on the plastic (regularator chip?) cover. Those say "ground here to test". (green line in pic)

I - not used? (blue line in pic)



What about the old voltage regulator and the connections to it? Pull it and the wires?

This can't be that simple. Please enlighten me before I do something dumb.

Thanks in advance!

 

this diagram should help..

note the fuse between the red and yellow leads at the battery
this lets the yellow lead know if the fuse blows, and cuts the alternator output..

also note the light green/red lead used to indicate power on. notice the resistors in line.. won't work without it

this worked on a 95 amp like yours, and my 160 amp.

and u don't use the old regular, this has it built in

Sam

 

Here's something that may help...

 

Boz,

here's a link to MAD electronics.... really good tech on alternators... 1 wire vrs 3 wire and some good sound information... look around the site some for some other cool stuff too

this might help

john

MadElectrical.com - Electrical Tech

 

Thank you Sam, Vern, and John!
That's exactly what I needed. The only thing I'm missing now is the inline fuse.
Also...the diagram says 6ga for the charging wire...is that really necessary? I have a roll of 8ga and I know I've seen 10ga in another truck.

Thanks again.

 

Depends on the output of your alternator. I think the 8 gauge would work for anything up to 100 Amps...

 

Thanks Vern.
It's the 95 amp 3G, so I should be fine with the 8ga.

 

my diagram says 8ga for 130amp

Sam

 

Almost done.
All wired up and I'm only missing the in-line fuse. Can someone educate me on that? I've seen the inline fuses rated anywhere from 60a to the 175a mega fuse like in the diagram.
For a 95 amp alternator, would the 175a fuse be too much fuse?
Why is the fuse rated so much higher than the output of the alt?
Won't the wiring, battery, and alternator cook-off before that fuse pops?

 

I assume you are referring to a fusable link. I've never used one but if you feel safer doing so put it in the Bat wire between the alternator and the Ammeter or alternator and starter solenoid. I'd use something like 12 to 14 gauge wire since you are using 8 gauge for the Bat wire.

 

So I reconnected the battery wire on this today, and while making sure all the bolts were tight I touched the alternator, and it was hot. (it sat for about 2 hours with the batt. connected before I noticed the heat issue on the alt.) Truck has not been started. I measured the temp on the alt. housing and it was at 120 degrees. From just sitting there.

I do not have the mega fuse installed.
The charging wire runs directly from the post on the alternator, to the battery post. (8ga wire)

I removed the charging wire at the alternator, and the temp has dropped down to 92 degrees in about an hour.

So, should I cut the charging cable and connect it to the hot side of the solenoid?

Because there is no megafuse, is that causing the current to flow into the alternator and the resulting heat?

 

More info...

It's not the charging wire.
I've had ONLY that wire connected to the alt. for the last couple of hours, the temp hasn't changed. Voltage on alternator post is 12.3.

Voltage on the "A" (regulator) connection wire (blue colored wire) that runs to the "hot" side of the solenoid is 12.3.

Voltage on the "I" (regulator) connection wire (brown colored wire) that runs to the ignition/keyswitch is 12.3.

The ground from the alt to the frame is tight, and on bare metal at the frame.
All the above voltage readings were taken using this ground point.

 

Wish I could help but I'm lost. Don't know what you have going on there unless the alternator possibly has an internal short. Maybe someone else has an idea...

 

Fixed.
The wire that was connected to the "I" terminal on the alternator internal regulator was supposed to go to the ignition post on the keyswitch. It was actually on the "batt" terminal of the keyswitch. Moved that connection over and monitored it for a few hours, no change in the temp on the alt.

Once the battery charges up, I expect her to fire right up.