B4 Alternator wiring??

SuBaRiNo · Post by **SuBaRiNo** » Sun Sep 09, 2007 11:57 am

Anyone had any experience with these. I bought a "SUBARU" alternator off ebay... turned up and it has a 3 pin plug on it which i think is off a B4.

I have been playing around with the wiring and m,anaged to get it to charge but i can't get the charge light to come on in the dash when the ignition is on but car not running. ALso it seams to charge at a peak of 15volts.

Can anyone shed any light on these or any information what so ever about them... wiring?? wire colours??? Anything at all??

Dave

Gannon · Post by **Gannon** » Sun Sep 09, 2007 12:50 pm

I assume you are putting this B4 alternator on your EJ22.

Does the EJ22 have a 2 pin plug? What are the markings on the case of the alternator?

Im a little worried that your getting 15v of charge, your battery wont last as long charging at those voltages.

The fact that the charge light isnt coming on sounds like a wiring problem

If you can get charge wiring diagrams for both, i can have a look at them and compare them.

SuBaRiNo · Post by **SuBaRiNo** » Sun Sep 09, 2007 1:05 pm

yeah sorry i missed some vital info there... putting it onto my EJ22 motor. I can't find any wiring info on the B4 alternator... although there is a sticker on the Alt assigning letters to the pins.

I think the letters are L, C and I.... I thought L was Light, C for charge and I for Ignition. Weird thing is... i can hook it up like that and it still has high voltage and i can even remove all the pins except the L pin and the thing still runs.

I know the wiring off the EJ22 harness and from there on i know there is no wiring faults. Im no stranger to working on Alts and automotive electrics but this new Alt has me stumped.

It never seams to go above 15volt though. 14.8 i belive to be a safe voltage so its not too far off but im still concerned.

Can anyone with a B4 confirm there charging voltage??

I also have the factory loom to plug into the Alt so i do have the appropriate wire colours to... if i could just work out what is 100% for what.

Dave

stamp_licker · Post by **stamp_licker** » Sun Sep 09, 2007 1:33 pm

This may help you out showthread.php?t=4260.
Maybe not, what happens when you put load onto it .The late model alt i fitted had no connection to ignition only the early ones had this.

SuBaRiNo · Post by **SuBaRiNo** » Sun Sep 09, 2007 4:39 pm

Great link... thanks...

So C doesn't get used??

And S should go to constant power? or would Ign make more sence??

Under EXTREAM load... running everything i got... volts do not change.

Dave

SuBaRiNo · Post by **SuBaRiNo** » Sun Sep 09, 2007 6:43 pm

Ok i pulled apart my old alternator and my new one... turns out the parts are not interchagable and i think i broke both of them. grrr

comparing the 2 internals... the ej22 alt which was working has rectfiying diodes as i would expect although the B4 alt one are missing and apear like there has never been any ever in there.... weird.

Dave

Dave

stamp_licker · Post by **stamp_licker** » Sun Sep 09, 2007 7:18 pm

Is it a green plug?You need to connect all the wires on the plug.When i did mine the wire coming from the ignition to the early style alt wasn't used[ealry ones need to be told they are on ,later ones do it a different way]when i fitted a later model alt.

SuBaRiNo · Post by **SuBaRiNo** » Sun Sep 09, 2007 7:58 pm

Ok... wrestled with this thing all day... got it going again... now i have only connected the L wire and the S wire as suggested in the post... the C wire i have left off and now it appears to be working perfectly. I still have no idea what the C wire is meant to do.

Thanks for the help

Dave

mattims · Post by **mattims** » Wed Sep 12, 2007 7:59 pm

my b4 one was bigger (physically - no idea about actuall charge capacity) and had the green 3 pin plug. i Have replaced it with a smaller (normal wrx/lib) one and it seems to work the same. So i dont think its only the b4s that have the 3 pin plug. I did however get one that didnt make the charge light go on and i was told it was "broken". They replaced that and it works now.

greywarden · Post by **greywarden** » Wed Aug 24, 2011 7:12 pm

stamp_licker wrote:This may help you out showthread.php?t=4260.
Maybe not, what happens when you put load onto it .The late model alt i fitted had no connection to ignition only the early ones had this.

holy cow. i think this is what i need buddy. whether you are still active or not thank you so much. love it. so far no questions for now i will just follow the guide that stamp_licker provided. thanks! you just save lot of my time finding solutions to my alternator i dont wanna replace this one!

d_generate · Post by **d_generate** » Thu Aug 25, 2011 5:50 am

You owe me 4min of my life for making me read a 4yo thread of dead.

Gannon · Post by **Gannon** » Thu Aug 25, 2011 6:33 am

d_generate wrote:You owe me 4min of my life for making me read a 4yo thread of dead.

Thats nothing, I flamed somebody on RSLC in a thread that was 3 years old, I felt a royal twit

d_generate · Post by **d_generate** » Thu Aug 25, 2011 6:29 pm

LOL, shits me when I forget to look how old they are. Should lock any thread that's untouched for over 18months.