3G alternator wiring questions

[Danny128]

Hey guys,

I'm currently in the process of upgrading the alternator on my 1970 Bronco and have a few questions about the wiring.

I'm following the wiring diagram below and am using a '95 Mustang 3G alternator with the wiring plug below. My current questions are:

1) How do I go about finding which wire connects to the ammeter? I read that that I have to make sure to remove this and can add a voltmeter later.

2) Where do you all typically splice into for the switched power source that connects to the pigtail on the alternator?

3) Can I completely unplug and remove the voltage regulator?

I know these are probably pretty basic for some of you, but I just want to make sure I'm doing everything properly.

Thank you,
Danny

 

[70_Steve]

1) How do I go about finding which wire connects to the ammeter? I read that that I have to make sure to remove this and can add a voltmeter later.
Remove the heavy gauge black or black/yellow wire from the original alternator and just tape it up. The output of your 3G will connect directly (or indirectly, through a fuse) to the battery. Doing that will make the ammeter inoperative.

2) Where do you all typically splice into for the switched power source that connects to the pigtail on the alternator?
There is a green w/red strip wire (904) currently going to the voltage regulator connector. That is the hot-in-run wire. Remove all the other, and remove the voltage regulator.

3) Can I completely unplug and remove the voltage regulator?
Yes, see #2.

 

[Danny128]

Thanks for the help, Steve.

1) The black/yellow stripe wire that was plugged into the alternator is one of the three in the picture attached, I think. So, just tape the harness end off?

2) I've also attached a pic of the harness that was plugged into the voltage regulator. There are 4 wires coming out of it, and the one farthest right in the pic appears to be red/green, but it's hard to tell. Do I just cut right behind the harness and splice over to the alternator?

I'll reground the thicker ground wire shown but am not sure what the left most wire that has the small canister attached is?

Thanks again for all the help.

 

[70_Steve]

1) The black/yellow stripe wire that was plugged into the alternator is one of the three in the picture attached, I think. So, just tape the harness end off?
Yes, just tape that end off. That was the output of the stock alternator, and will be hot all the time. So do a good job taping that off!

2) I've also attached a pic of the harness that was plugged into the voltage regulator. There are 4 wires coming out of it, and the one farthest right in the pic appears to be red/green, but it's hard to tell. Do I just cut right behind the harness and splice over to the alternator?
Green w/Red stripe should be second from the end. Orange wire is on the end. Remove the little can (capacitor) completely.

 

[Danny128]

Thanks again, Steve.

Here is the final product. I rewired the battery terminals and the starter power, relocated the solenoid, and mounted the mega fuse holder.

I'm not quite through, though, because I need to get a new bottom mounting bolt/nut since the new alternator's mounting hole isn't threaded.

Danny

 

[70_Steve]

I'm not quite through, though, because I need to get a new bottom mounting bolt/nut since the new alternator's mounting hole isn't threaded.

Danny

If you want it "like stock" you can drill, tap and install a helicoil in that bottom hole. That's what I did. Comes in handy as you're tensioning the alternator with one hand and tightening that bottom bolt with the other.

 

[Danny128]

Steve,

I just got the helicoil kit to make the alternator "like stock," as you said. A few quick questions:

1) Did you tap the hole all the way through?

2) The helicoil inserts that I have appear to be about half the depth of the mounting hole in the alternator. Did you run into this? If so, did you use multiple inserts or just one and run it all the way down?

Thank you.