Alternator from 06-07 B9 Tribeca - 3pin connector?

[free5ty1e]

So, to recap (from this thread on my AC compressor's unseizing:

Got an alternator from a 06-07 B9 Tribeca from my mechanic, score! Includes the 3pin connector and pigtail. I'll take a photo...anyone know what the three pins/wires are for?

Looks like it has:
Black with red stripe
White with red stripe
White with black stripe
...or did I perhaps end up with a different 3pin connector pigtail here not for an alternator?

Any idea on the amperage rating on this thing? Not really sure what model year it came from, it was sitting in a pile of spare parts that were likely good. Says Mitsubishi on the alternator itself, hmm...sure looks like it will fit right in place no problem. Although it looks like I'll have to drill out the existing ring connectors to fit around that huge bolt... and find a nut to go on top, as well. That's a ground, right? Should I also run a new cable directly to the battery's ground while I'm working with this part? I plan to do the grounding mod soon to this car anyway, if that's a ground then I should probably include it.

[James614]

Don't know about the harness colors, but that ring terminal is the power out, and its grounded through being mounted on the engine. I actually have no idea what the connector is used for.

[rallyak]

I wander if this helps http://www.bbs.legacycentral.org/viewto ... 19&t=49364

[Legacy777]

It looks more like it came from a B9 Tribeca (06-07) vs. a Tribeca (2010-2011).

Alternator from B9 Tribeca

Alternator from Tribeca

Unfortunately, it doesn't list the plug info. Check out the pictures to confirm which alternator you have, and then we can maybe find out what the connections at the plug are for.

[free5ty1e]

Thanks guys, indeed between your two posts I think I got it figured out.

I have confirmed this came out of a 2006-2007 Subaru B9 Tribeca, but it doesn't appear to matter. Both have the same 3-pin wiring as far as I can tell.

Furthermore, the following two links show the connector's wiring in very simple diagrams in the upper right hand corners:
Legacy alternator - 70 Amp
Newer Subaru alternator - 90 Amp (awesome)

More specifically, here are the two little connector diagrams that show the pinouts: (edit - NOTE --- these are for the MALE connectors on the alternators themselves, not for the FEMALE connectors on the harness. If you are attempting to wire pigtails up, keep this in mind!!)
Legacy alternator 4-pin connector (#351):
Newer Subaru alternator 3-pin connector (#319):

So, it looks to me like I can actually wire in both plugs to my harness so my '92 Legacy Autotragic supports either style alternator. Is there any reason I should not do this (tap and solder) and instead should lop off the Legacy 4-pin connector and solder on only the newer 3-pin connector?

Also, kinda curious what the wires actually are for, tried looking at wiring diagram and it wasn't readily apparent (I need to get better at reading automotive wiring diagrams). Obviously the "IG" is for ignition, although I can't see why it would be needed. D? S? L? Then, as mentioned earlier, the big bolt is a +12V out directly to the battery and NOT a ground, correct? The alternator grounds through the mounting bracket? (and should I slip a ring terminal in there to run a new ground to the battery along with the other grounding mod points I'm aware of?)

[Legacy777]

You are really only going to use two wires, the S "Sense" & L "Light". So it's really up to you whether you want to make a plug & play harness or just convert to using the newer style alternators.

The older style Legacy alternators used an ignition lead to tell the alternator to turn on. The newer alternators use an rpm based signal to turn on once the rpm goes above like 200 rpms or so.

Here's a quick answer to what the sense & light terminals do. The sense lead essentially monitors the system voltage and adjusts the alternators voltage output in order to maintain proper system voltage. The light lead is connected to the charging system warning light and if the alternator is not making enough voltage, it will cause the charging system light to illuminate. This site has a little more detailed information if you're interested.

http://bob_skelly.home.comcast.net/~bob_skelly/alternator_conversion/wiring_alternator1.html

The big bolt on the alternator is the 12v output and needs to go directly to the battery.

Yes the alternator grounds through the bracket and engine. I don't think it's necessary to run a separate ground to the battery, but I don't think it'll hurt anything if you do.

[free5ty1e]

Awesome, thanks once again Josh! That is exactly what I needed; makes sense now.

I must owe you like a case of beers at this point for all your timely help; if your recent trip brought you closer to the Portland area I'd have attempted to buy your meals at least. You coming to WCSS by chance?

...anyway, I'll just need to drill out these two ring terminals that go on that big positive output bolt so they fit, looks like there is easily enough material if I select the bit carefully.

I think I'll retain both connectors in the setup, in case I ever have a need to install a Legacy alternator again. Also, bonus, I can return the Duralast if this works and use that cash for something better.

[Legacy777]

You're welcome.

Unfortunately no I won't be up for WCSS. I will have to try and make it one of these years...

Yeah, I'd return the duralast alternator regardless. They are not durable and they don't last...

[free5ty1e]

...

Yeah, I'd return the duralast alternator regardless. They are not durable and they don't last...

I figured -- so it was just a clever name. heh

[free5ty1e]

(Edited - reading connector wrong!)
D is neither pinned nor wired in my '92 SS. Guess it dont matter.

I still have to find a nut to fit this large output + bolt. Probably going to have to head over to Home Depot and look through their hardware. Anything in particular I should look for? What types of metal are OK to use here? Is the alternator bolt + brass? Probably should get brass, in that case...

[free5ty1e]

Score, my mechanic had the correct nut lying around in his spare parts; I have everything I need, upgrading to the Tribeca alternator this weekend.

Still curious as to the function of the "D" line on Subaru alternators... I'll figure it out later, I know what to do with it at least

[Legacy777]

That is not D, that is the Ign lead!

You more than likely have the orientation incorrect when you're looking at plug. The diagram posted above is probably looking directly at the alternator.

[free5ty1e]

Ah yes I had just realized that those diagrams are for the MALE connectors, not the FEMALE connectors. Therefore, I was reading the diagrams backwards!

Mirror image, now they make sense.

Edit: That's not IG, that's the Sense line. It's the horizontal pin on the right (on the female / harness connector) under the plastic retainer.

[free5ty1e]

Well, got it all wired up...

Only using, as Josh mentioned, "Sense" and "Light" lines. "Ignition" is not used on the newer alternator, and "D" (still no idea) is not pinned in my Legacy harness.

Unfortunately, I didn't test fit the Tribeca alternator as fully as I should have before diving in, and it just straight does not appear to fit. It looked the same but the replacement alternator from Autozone went in very easily whereas I was pounding on the Tribeca alternator with a rubber mallet trying to get it to seat in there. Just could not seem to make it happen. So perhaps the 90 amp alternator upgrade is not to be. Oh well - doesn't look like I have a drill bit large enough to ream out those ring terminals to fit over the enlarged bolt + output.... I'd probably have to run a new alternator -> battery + cable of larger gauge anyway to make this install safe.

Maybe if I find one that fits....

[James614]

Its possible the fitment issue comes from the fact that the Tribeca doesn't use an EJ motor (EZ30/36). But I can't be certain, it could have just as easily been a change across the line at a certain year.

Does it simply not slide over the hinge bracket? If so, you could try grinding the alternator's ears ever so slightly to give it the clearance it needs to fit.

[free5ty1e]

I couldn't seem to get the alternator to angle in there correctly to squeeze onto the hinge bracket; the front kept hitting the adjustment bracket. It may be possible to grind away enough material in the right locations to allow this to squeeze in there. I keep thinking its much bigger than my normal Legacy alternator whenever I try to squeeze it in, but when I compare them they don't look much different visually.

I'll hold on to it but will have to run the Duralast for now, unfortunately. Gonna wait for a cooler day to go junkyard alternator hunting.

Anyone know of any good junkyards besides the ones listed at Row 52 in the Portlandish area? The one I went to last time wanted $50 for airflow sensors, I'm thinking perhaps a smaller junkyard might have better pricing and may not be listed in Row 52. Gonna search around and see what else I can find, maybe I'll try the Pick n Pull in Sherwood and see if they have anything decent.

[Legacy777]

Edit: That's not IG, that's the Sense line. It's the horizontal pin on the right (on the female / harness connector) under the plastic retainer.

I am pretty darn sure I did not use the larger white wire, but would have to double check...

[free5ty1e]

I inferred this from the position of the wires vs the positions of the pins.

Havent tested the 3pin connector with an appropriate alternator yet anyway but would be nice to know if ive got it wrong.

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[free5ty1e]

Just wanted to share; the thick white Sense wire going to our alternator's 4-pin connector is just spliced into the main output line, not actually a voltage return from elsewhere in the system:



If this is the case, I don't see why I couldn't just slap a ring terminal on that line and add it to the alternator's output bolt - should be equivalent, and no splicing to my new alternator output wires that I'm running now. Anyone think of a reason why I shouldn't add the Sense line directly to the output bolt as a ring terminal?

[free5ty1e]

Heyyyy.... these output cables don't go directly to the + of the battery. WTF? They disappear under the fuse box into the fender. I was planning to just run a new set of 3x 10 gauge cables from the alternator output bolt to the battery's positive terminal. Where do these go?

It's too late for me to try and figure out this right now.

[free5ty1e]

So, after looking at some wiring diagrams and reading other posts, it appears that the alternator main output cables get routed eventually to the fusebox and distributed to a couple other points including the starter and battery.

I'm not replacing all that cable. The burned / damaged part is within the last half foot or so near the alternator output terminal.

Gonna cut the orig 2x 8gauge cables short at the battery, wire up directly to the + terminal, then run a 6 gauge wire directly from the alternator + terminal to the battery + terminal. Should be just as good, if not better.

Anyone see any reasons why I should not pursue this course of action?

Edit: Might as well run a smaller Sense wire alongside the main output, that way it reads actual system charge voltage instead of spliced in 4 inches down the main output wire as Subaru had it. 16 gauge should be beefy enough for Sense, correct?

[free5ty1e]

My assertions appear to be correct. Car started right up this morning to test the new wiring out. Big difference... system voltage in the cab on my volt gauge now reads a steady 14.2 - 14.5v! Before it would typically regulate at 13.8 or so with the old wiring and sense line connected near the alternator output... the light are brighter and the car feels even smoother!

Next ... timing belt and seals on my 92 ss...

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[free5ty1e]

By the way, over on nasioc there are 3 major electrical system upgrades to all used subarus: alternator output to battery +, engine block to battery ground, and chassis to engine ground. I now have the trifecta, as it were.

Gonna definitely do this to my 92 and 91 too!

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[Legacy777]

The "engine block to battery ground" really isn't that important. Running a line from the ECU ground point on the back of the driver's side intake manifold to the battery is what you should do. That point is where all the sensors and ECU ground through.

[free5ty1e]

Looks like a good ground is already in place there to the battery negative terminal. ...in my 92ss as well, which must mean its a stock wire. Is that huge black w/red stripe wire typically needing replacement or backup after 200k miles or so? Hmm, I will read continuity and resistance on that wire and see what shape its in.

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