Hi guys,

I’m from Hong kong and my scooby is MY04 EDM STI with EJ207

two months ago , my alternator loom shorted and burned a little bit , then I took it to mechanic replaced the loom

after that it will getting P0558 engine code and only showing 11.8-12.3v when cold start

But it will be fine when running about 5-10mins , the voltage will be pull up to 13.8 to 14.5v
and the p0558 code will not show up after I clear codes

one day my battery going flat and I changed it

another day the alternator is not charging all the time , then I replace a healthy one on it

but the problem is coming back again and again

and now it’s not charging anymore, tried to replace battery and alternator again
and tried to turn on parking light and climate control when running engine
But it won’t charge at all

already killed 3 batteries in these two months lol

I search this problem in google and bring me to here , lots of MY02-06 scooby got this problem and discussed, but I seen every post , there is no solved results

Anyone got this problem and completely solved? Please tell me the way

I’m going to mad with this problem and don’t have another car to use in this Christmas and new year

Wish all Merry Christmas , thank you

 

Have you checked the big fuses in the engine bay, after the short were all the fuses checked in-case the short had caused other issues?
Was the replacement a genuine alternator ?
Are you sure the loom fitted was the correct one?
Does the battery bulb light up on the dash when you start the car,
If the car does charge and you still have drain issues it could also be the alarm or tracker batteries dead.

 

Hi, @JDM_Stig

Have you checked the big fuses in the engine bay, after the short were all the fuses checked in-case the short had caused other issues?

-mechanic said if the big fuse dead, my car won’t start , and no reason to suddenly charging again before when the engine warm up
but it’s not charging all the time right now
so maybe need to replace a new one 80A?


Was the replacement a genuine alternator ?

-tried 3-4 used genuine alternator , all working nice on other car , but not mine



Are you sure the loom fitted was the correct one?
-that’s not a exactly same loom , from a MY02 legacy B4 turbo , but I think that was a upgrade (maybe thicker than Impreza) and done by a professional mechanic


Does the battery bulb light up on the dash when you start the car,

-before burn : yes
after fixed : no
This is the first way I’ve seen here and I ask mechanic to try it
but he said that he tried but not working


If the car does charge and you still have drain issues it could also be the alarm or tracker batteries dead.

-the car doesn’t charge anymore right now
because my pioneer player show up real time voltage very well (I’ve tried to compare with)
Last time I drive it about 10mins on highway and it’s says 11.5v
and my battery keep going flat to 9.0v then it’s break down in the tunnel





without changing bulb light and 80A big fuse, anymore ideas?

thank you so much @JDM_Stig


Here is this bad boy :

 

Check the IG fuse in the fusebox if the charge light isnt working ( inside the car by the drivers knees )