Alternator wiring diagrams: 1G, 2G, and 3G

[sly]

You can fish them out of the headlight harness if you ever have the ambition to do so.

I thought about this... then I saw the sheer amount of re-taping needed and said... NO. I just cut the fuse link off on the battery side of the car... removed the link from the starter solenoid and tossed it. If I ever get a serious motor to go into that car... THEN I will consider removing that trash. The extra 3-5 pounds of wire ain't hurting anything.

I'd have to be really epically bored to even consider doing this without having dern near everything out of the front of that car.

[1987cp]

Amusingly, I had the headlight wiring out of my car a couple years or so ago to make some repairs, but at that time I was still making use of the old stock alternator wiring. It's actually not that big a deal to fish the headlight harness out of the nose of the vehicle, and if nothing else it'll be happening if and when I get around to upgrading the headlights to a relay system.

[BerniniCaCO3]

Hey--
Looking at the wiring diagrams, and then at the alternators, the sole difference was that the y/w wire, in the middle of the harness, disappears into a main loom for the 2g, but for the 3g, loops over to a little single-wire harness right next to the main one?
That, and put in a bigger charge cable. Otherwise, the 2g harness plugs right in? I should be good if that's the case. If there's any reason why you would cut off the 2g harness altogether and need to custom solder on the 3g harness, then I've done it wrong.

Starting up my engine after sitting for 3 weeks, battery light came on about 5 minutes ago, but there are lots of reasons why the battery light could come on. Just want to make sure it's not the alternator wiring

[sly]

right. The only reason I soldered the 3G harness onto my car was that I didn't have to pull it out of the alt when I installed it. I have bad luck with those damn tabs.

[BerniniCaCO3]

hmm...
I recharged the battery last night: I have a jump box, so I plugged in the jump box to charge, and then I hooked its cables up to my battery as if to jump it.
Unless I learned my electricity 101 wrong, that ought to charge both the jump box AND my car battery together.

Checked it this morning, battery reads 13+ volts. Seems charged to me.

Battery light is still on though...
Could there be something I did wrong with the alternator wiring that could have messed with the dash idiot light?
In the original harness, the black wires are now disconnected, as I have a new 4gauge charging cable,
AND the Y/W wire was different on the 3g alternator, it looped back to another spot on the alternator rather than disappearing into the loom.
By clipping that, could I have cut off the idiot light, so now it sees 0V and thinks there's a problem?

[1987cp]

Only thing going to the idiot light is the wire to the field coil. And your alternator obviously won't work without that attached.

[BerniniCaCO3]

I don't actually know that it is working
could anything on the old harness be backwards from the new 3g alternator, any of those 3 wires in a different spot?

It does sound like something's off, doesn't it.
I'll plug in a spare, if dysfunctional, 2g alternator and see if the light goes off.

[87gtVIC]

The idiot light is the red and green wire that actually runs power through your printed circuit (idiot light) and tells the alternator to turn on. It also has a resister built into it to light the idiot light because it senses something is wrong. Do you have the belt on the car? are all of the connections tight and secure is the alternator a new or used one?

And the voltage regulator plugs are the same between the 2g and 3g. No wires would be in different positions.

[BerniniCaCO3]

OK. I'm going to switch back the W/BK wire and see if that does anything.. even though it shouldn't.
Hmm, the charging cable-- that can go to any hot, right? Well, not any, but it's ok being on the fender starter solenoid, the continuously-hot side of course? Or is that my trouble?

Yes, it's being actively run. Oddly, I'd had the old alternator plugged in and not being driven at one point, and the battery light was NOT on.

It's a used one, but I had it tested at salvo and it tested fine. Put in new brushes.

[87gtVIC]

Starter solenoid is fine for them. What do you mean by switching back the white and black wire. The white and black wire should be the wire coming from the voltage regulator to the singe spade terminal on the alternator itself.

[BerniniCaCO3]

right, and that was the only wire I changed from the 2g harness. It used ot disappear into the loom... if I wire it back the way it was (into the loom, instead of to the spade terminal)?
Yeah, it doesn't sound right to me, either.

[hypostang]

The only wire you need to reuse on the car is the green wire
This is how it should look

[BerniniCaCO3]

Ok-- so you have the green wire going back into the stock wiring loom?
Where do you have the yellow wire going to? I reused that wire, too.

[BerniniCaCO3]

I figured the yellow wire in the stock harness already had to go back to hot, somewhere-- so I could just leave it be. Would that result in the alternator just not functioning?
I tested earlier, in fact, my battery voltage DROPS when the engine is on. Voltage must be backfeeding into the alternator, it's not keeping up.
Should I take that yellow wire and loop it directly over to the fat red charging cable?

[hypostang]

The stock yellow wire is connected to the starter solenoid with the stock black / orange stripe wire,at the end of a fuse link , If you disconnected the stock black/orange wire you disconnected the yellow also .


Take the yellow wire and loop it around to the charging post like in my earlier pic and you should be all set, this should make it a little clearer