Hi !
have a problem on my impreza v5 sti type RA JDM.
The alternator won“t charge .
I have change the alternator to a new one but the new one won“t charge the battery as well.Checked with a voltmeter.
The battery lamp in the dash don“t works as well.
I have checked the ground/earth wires,kables and so on.
The battery is brand new also.

Anyone have the same problems ?

/ Dennis

 

Not on a subaru but ive got a couple ford transits and one did exactly the same.So i did what you did fitted a new alternator still no charge,i didnt have a charge light either so i checked the bulb which was blown,and believe it or not put a new one in and it charged.Put the old alternator back on and that one worked as well,so it was definitely the bulb that caused it,perhaps subaru are wired the same way.

 

I also have thought abot that becouse the lamp grounds/earths to the chassie. But our newer sti“s have not a bulb just diods with chips.
And what I could understands is that the alternator have three pin. One for the signal from the engine ecu that tells how much the alternator to charge. On this pin I don“t have a signal.

 

Do you know where the diode is in the loom,that will cause it to fail.I had one go on a bike and lost charge,it took me hours with a multimeter until i found a dead one and when i replaced it the charge came back.If i remember rightly it was used as some sort of non return valve.

 

I remember an early rally Escort I fitted an alternator to. You HAD to ensure the bulb was OK, or it didn't charge.

 

there is no bulb/lamp .have take the dash/speedo out and checked. Just a diode but it can“t be replaced.

 

Can you multimeter it to check for resistance?

 

checked with the contact(with is placed on the alternator) pin for lamp and to battery(+) but it won“t "beebs"
(checked the beeep function on the multimeter,don“t know what it“s called .)
Checked with a friends sti and it beebs between lamp-pin and battery(+)

 

Yes its quite strange,i never did find out why and after a day of checking everything i was just glad to get charge back.Was it your escort? thats what i always kept mk2 rally escorts before subaru,i still miss them now.

 

Sounds like thats the problem,theres probably a diode in line somewhere to stop power feedback,at least there is on fords.

 

Sorry ive only just noticed you have a v5 i thought you had a newer one that i havent seen with a voltmeter or something.Ive just looked the v5 up and there should be a ignition light which is if its not working the charge will fail??

 

Have looked at the back of a v5 jdm sti and the bulb holders look like diodes,have you tried twisting it anti clockwise and pulling it out??

 

I'm having similar problems, that my alternator won't charge, and I've just fitted 5wks ago a new battery. This Has now succumb to weekly charging of the battery, but in the last 4 months of having this alternator problem, my batt and ignition lights are fully functional as, when battery goes flat the battery light and ignition light will either dim or not light up at all depending how flat the battery is.. Also when the battery has been fully charged the batt & ign lights are lit and go out once the ecu has checked the operation of these components just after the engine starts. These lights have Never flickered or came on at any time during the last 4 problematic months giving me no warning of a loss of charge, u just notice one day roughly about 1 wk after fully charging the battery, that acceleration has kinda dipped away.....I've been told the car is best to be data logged but at nearly £90 + vat I'm just after some knowledge of what i could check first as I've checked earth/ground wire looks ok as car is only 31000miles old and is pretty new looking in whole engine bay........anybody with newage imports came across this before?..

 

No the "warnings, diodes" check engine, parkingbrake, battery are diodes and they are "solder" to the cluster mainboard, you cant take them out or twist them.

 

Ahh that's where the confusion is,i was thinking of a ordinary (diode), so these clocks use leds ( light electrical diodes) .My bet is the same rule applies so it needs a new one soldered in to complete the circuit.

 

we put the dash/speedo in to another sti and all the leds are working so nothing wrong with the dash.
We have tested to change the ecu also but it works also -nothing wrong there.
So the dash,ecu,alternator and earth is ok but the problem still remains.
/ Dennis

 

I think you hit on the problem in a earlier post, apparently if the alternator doesnt receive 12v from your ignition switch when you turn on it cant charge.It just so happens this power feed is shared with your ignition led so it looks like theres a break in the 12v feed.This would explain why your buzzer goes off when you connect from the alternator to the battery on your mates car and not on yours.

 

yep could be, but what cable is it ? I dont got any workshop book on the car so dont know where to start

 

http://www.volkszone.com/VZi/showthread.php?t=288955

Heres a thread on how to wire the alternator,ive got a diagram but the links down at the moment will try it later.

 

Just found this it shows a 12v feed coming of a 10amp fuse

http://www.northursalia.com/modifica...ingdiagram.pdf

 

Sorry only just noticed this,you can do a easy earth check by putting a jump lead from your neg battery terminal and clamp the other end on the alternator body,it sounds a like a dodgy alternator tbh you need a multimeter to check what voltage is reaching the battery when the engine is running.