Subaru Alternator Wiring question

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 · 22 Sep 2006, 7:44 pm

#537015

Hi guys & girls.

I wonder if anyone could give me some guidance please:

My Scooby alternator has 3 thick wires (white), these are joined together (from the factory). There's also the thin Alt Light sender wire.

One of the thick wires must be the excitation coil and the other two 12V power outs.

Do you just connect the thick wires directly to the battery or should they be switched through an "Ingition On" relay?

Sorry if this sounds like a stoopid question, I just don't know

Many thanks.

1303 Officially Full-On Dubber

250 posts · joined Sep 2003 · 22 Sep 2006, 8:09 pm

#537023

Normally they have a sticker next to the plug on the alternator. Hitachi, Nippon etc...normally.......

IG is ignition supply (it is important not wire this up the permenant 12v + as it will drain a small amount of currentn trough the regulator and rotor)

S is permenant 12v + supply This wire actually lets the regulator know how much drain is on the engine, closed loop principal

L is light...pretty obvious

and the main battery post should have heavy guage wire connected to the battery or starter motor depending on how it is wired.

These are a higher output than any VW alternator, so if you are running extra load you should run a bigger wires from the alternator to the battery than standard vw

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 · 22 Sep 2006, 10:28 pm

#537068

1303 wrote:Normally they have a sticker next to the plug on the alternator. Hitachi, Nippon etc...normally.......

IG is ignition supply (it is important not wire this up the permenant 12v + as it will drain a small amount of currentn trough the regulator and rotor)

S is permenant 12v + supply This wire actually lets the regulator know how much drain is on the engine, closed loop principal

L is light...pretty obvious

and the main battery post should have heavy guage wire connected to the battery or starter motor depending on how it is wired.

Thanks for the reply.
On mine the three thick wires are actually crimped together from the factory. I didn't get a front clip, just the engine and loom, so I can't look at the original set-up.

There's no sticker either. 🙄
I wondered about switching the three through a heavy duty relay energised through the relay but I'm sure that's not the best solution.

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 · 24 Sep 2006, 9:37 am

#537373

It's looking like it could have been wired direct to the battery via a 1.5mm Fuseable Link.

Can anyone confirm/deny this please? I can't be the only one with an alternator like this, can I?

lexm Commited Dubber

57 posts · joined Apr 2004 · 25 Sep 2006, 12:07 am

#537643

Sounds like an EJ22.
go here
http://www.finleyweb.net/default.asp?id=142
get the ej22 service manual part 2 and have a look at page 117 of 162 of the PDF file.

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 · 25 Sep 2006, 5:07 am

#537661

lexm wrote:Sounds like an EJ22.
go here
http://www.finleyweb.net/default.asp?id=142
get the ej22 service manual part 2 and have a look at page 117 of 162 of the PDF file.

Thank you, my friend. 🙂
It does go directly to the battery via the link.
It's ment to be a 98 EJ20.

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 · 26 Sep 2006, 10:01 am

#538116

Hi

Slightly off the subject, in stock Subaru’s some have 3 small connections at the alternator for the voltage regulator. Cars with this type of alternator have the charge rate governed by the ECU and it is very common for them to show 12 volts or just battery voltage when the car is running, when a load is applied the charge voltage will increase to around 13 – 14 volts. This condition can often be mistaken for a faulty charging system.

Steve

lexm Commited Dubber

57 posts · joined Apr 2004 · 26 Sep 2006, 1:19 pm

#538165

Any idea which models this applies to or any further information available please.

1303Steve wrote:Hi

Slightly off the subject, in stock Subaru’s some have 3 small connections at the alternator for the voltage regulator. Cars with this type of alternator have the charge rate governed by the ECU and it is very common for them to show 12 volts or just battery voltage when the car is running, when a load is applied the charge voltage will increase to around 13 – 14 volts. This condition can often be mistaken for a faulty charging system.

Steve

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 · 27 Sep 2006, 9:25 am

#538511

Hi

Its the later models, they are identified by the 3 wires instead of the 2 on most other Subarus.

Steve