jase128

hi all......am tryin to sort out an electrical problem on my05 wrx...what voltage should i expect from my alternator?,the magic figure being quoted between 13.5 and 14.5 volts at idle speed but will i still get this with battery at fully charged state and no electrical load? ie..lights and heater on.

jase128

bump

prodriverules

iTrader: (52)

You might see a .5 volt drop but should be up above 13-13.5 all the time whether under load or not and same applies to fully charged battery mate it will not effect the amount of charge that should be produced by the alternator

jase128

i've just retested the alternator and only gettin 13v or over when load is put on(eg lights)but im gettin no charge circuit warning

prodriverules

iTrader: (52)

as long as its just over with no warning light it will be fine mate,be shore to check at night to see its not just slightly illuminated.

rob84

iTrader: (5)

The alternator runs a step type charging system or as known in other ways intelligent charging. the ecu switches the alternator on and off depending on load, no lights or anything on you will find it wont charge at all until it drops below 12v or you turn a load on I.E sidelights/heater/rear demister. some imprezas in the summer months complain about flat batterys as nothing is really being used it happened on my old one a few times

13v or above is ok for charge.

jase128

had heard about intelligent charging before...is it only subaru's that do this,the reason i ask is because the last time i tested the alternator i tried my voltage tester on missus car to double check the tester was ok and her car produces 14v straight from start.

rob84

iTrader: (5)

Usually find they are only fitted to performance cars, they switch off when not needed so the engine can perform to its full potential or something daft like that