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Subaru Alternator Wiring question
ElusiveStranger - September 22nd, 2006 at 07:44 PM

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 - September 22nd, 2006 at 08:09 PM

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 - September 22nd, 2006 at 10:28 PM

Quote:
Originally posted by 1303
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. :rolleyes:
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 - September 24th, 2006 at 09:37 AM

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 - September 25th, 2006 at 12:07 AM

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 - September 25th, 2006 at 05:07 AM

Quote:
Originally posted by lexm
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 - September 26th, 2006 at 10:01 AM

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 - September 26th, 2006 at 01:19 PM

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

Quote:
Originally posted by 1303Steve
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 - September 27th, 2006 at 09:25 AM

Hi

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

Steve