Need help wiring alternator - plug broken

Having a hellish time figuring out this alternator problem.

I bought this 2005 tacoma and it has been over charging my battery at about 15.5 -15.9 v. This killed my battery eventually.

The plug on the wiring harness is broken so the wires are connected directly to each tong on the receiving end of the alternator. One of the tongs on the alternator is broken off, so only three are connected. I have a new alternator and battery but want to make sure everything is correct so i don't waste 600$. I'm suspicious that the old one wires were connected wrong or that 4 wires instead of 3 should have been connected.

So my question is, given the configuration of wires in the fuse box, what configuration should they be wired in on the alternator receiving end? It seems to me that a green/yellow wire should also be connected. See images and description below. the current set up on the truck is like this:

alternator receiving end:
Top left - nothing (tong broken)
Top right - white
Bottom left - green
Bottom right - grey



heres the fuse box configuration:

 

This might help.
You need to under stand that the plug G2 is shown as if looking into the plug.
The plug-in on the alternator is mirrored of the diagram.

You might have a look at the Alt-S Fuse. See if some one tried to rig up a higher charge rate for an AGM battery. Doubtful, but you’re already in there doing work.

Take a look at the EB1 for an example.
The “Female” (Right side) is a mirror of the “Male” (Left side)
Make not of this while look at the plug-in G2 of ON THE alternator.

AGAIN, DON’T PLUG THE WIRES INTO THE ALTERNATOR AS PICTURED IN G2.
@caribe makaira - Help me out here man. Make that connector “look right” for this guy.

 

@caribe makaira

 

There should be 4 wires, hard to tell which one you’re missing from that pic since none of the wire colors are oem. Looks like some shade tree mechanic was in there tinkering before.

 

Worth mentioning, 4 cylinder charging wiring is different than V6. OP makes no mention of what he has.

 

Yes, pins 2 and 3 are different.

It looks like the 2TR (4 Cyl) uses 4 wires.
While the 1GR use 3.

OP, take a look over on the left corner of the diagram for the reference number.

 

thats true, for some reason the 4 banger ECM monitors the alternator field voltage. So maybe no missing wire.

 

Thanks so much for your input guys! These wiring diagrams a bit greek to me but if i stare at them long enough I hope to figure it out. Also sorry for not mentioning I have a 6 cyl

 

ok i think i get it, @caribe makaira. If i interpret your diagram right I should connect wires to terminals on the new alternator as follows:

Top left - green
Top right - white
bottom left - grey
bottom left - nothing

con anyone confirm that having only 3 connected (for a 6 cyl) is ok? still wondering if that green and yellow wire(seen in fuse box photo) should be connected. it snakes down to somewhere unknown in the wiring harness.

Again thanks so much this a huge life saver guys, much appreciated.

 

It's to the starter...

 

Ok update, not charging! Battery voltage drops slowly and steadily when running. Brand new battery, read 12.6 before starting.
I know I'm really turning this into a saga but i have little to no options for good shops here.

Pretty sure i wired correctly, ie mirror of the plug shown in diagrams from @TnShooter and @caribe makaira .
see below:

 

Verify the Alternator fuse. Just be aware that it's bolted in, not a pull out type.

 

Going by the pictures you have posted.
It looks like you may have the wires on wrong?
Double check the wiring.

The Green and Grey wires should be on the same side of the “bar”.
The plug is divided by the “bar”. 2 wires on one side and 2 on the other.



What do you think @caribe makaira ?

See the arrow below for the “bar”

 

Ok. I added “Bottom” to the plug.
Well refer to the bottom of the plug as the “smooth side”
See below.

It looks to me like the wiring should go like this.
Green wire goes to where you have the white wire now.
Grey wire to where the green wire is now.
And the white wire to where there is no where currently.

Again, let others voice their opinion.
I’m not always right.

 

I agree. Green wire need to be be swapped to the current unused terminal of that connector. The green is ignition wire to turn on the regulator so that would explain why it’s not charging.

Edit: never mind I realized that diagram was the connector end not the alternator end. I agree with your post above.

 

I think the whole thing is wrong?
Take a look at the plug side that’s marked “bottom” on both plugs.
If bottom and bottom “meet” when plugged in - the green wire would be where the white is now?

This is where I wish I had a computer.
No ability to edit or creat photos on an iPad.
Or I don’t know how to, I should say.

 

yes, mirror image. Had to play it out in my head. I’m on an iPhone so not much ability to doctor the photo to match what we’re looking at vs the connector end. Just like you posted earlier:
Green wire goes to where you have the white wire now.
Grey wire to where the green wire is now.
And the white wire to where there is no where currently.

 

There is also usually an alternator full field test you can perform which will separate an alternator issue vs voltage regulator. Not sure where the field terminal is on these alternators.

https://bgbonline.celicatech.com/89tech/alternator and regulator nippondenso.pdf