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Alternator Changed...but Still No Charge

Nismo_God

By Nismo_God,
in General Maintenance

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Nismo_God Veteran

Nismo_God

Posted
Posted

hi all,

i have fitted a 2nd hand alternator and no charge.

could it be another dud alternator?

what else could make an alternator not charge? i have checked the alt fuse and its good...checked all the other fuses and all good....

really want to get it back on the road this weekend....any help would be appreciated.

thanks!!

koduRB25det Community Regular

koduRB25det

Posted
Posted
hi all,

i have fitted a 2nd hand alternator and no charge.

could it be another dud alternator?

what else could make an alternator not charge? i have checked the alt fuse and its good...checked all the other fuses and all good....

really want to get it back on the road this weekend....any help would be appreciated.

thanks!!

Did u check for any voatage drop between alt + and bat +. it must be less than 0. same time check the Continuity test...?

Nismo_God Veteran

Nismo_God

Posted
  • Author
Posted

battery and + from alternator is the same voltage....

what is a continuity test?

its a new battery with 12.8v when charged....so battery is fine...

changed the alternator again and no charge....so either got another dud alternator or something else is stuffed....is there a way i can test the alternator itself? ie not connected to the car?

i have connected the thin black with that has the 10mil bolt....i have connected the earth clip...i have connected the positive to the alternator...am i missing anything?

Sifty33 Enthusiast

Sifty33

Posted
Posted

hey mate i just had a look at the alternator on my r32 and it has 1 large black wire (earth) one large white wire which runs to the battery, it also has 2 thin wires but i cant really see where they go although i think one of the thin wires should go to the battery or a 12v feed and somtimes these wires burn out due to the constant voltage running through them, also there would have to be a wire going to the dash for the charge light? does the charge light stay on when the car is running?

i have probaly been no help whatsoever but you never know

corin

Nismo_God Veteran

Nismo_God

Posted
  • Author
Posted

maybe that wire to the dash has burnt out...there was only the one thin wire to the alternator when i was taking it off...

does anyone know how to test if this wire is the fault?

Sifty33 Enthusiast

Sifty33

Posted
Posted
maybe that wire to the dash has burnt out...there was only the one thin wire to the alternator when i was taking it off...

does anyone know how to test if this wire is the fault?

hey the wire going to the dash wouldnt burn out, but maybe that wire doesnt come straight off the alternator on an r33, there needs to be 2 wires going to the battery or a 12v source (a feed and a return) im a 99% sure of this.

what i would try would be to join onto the thin wire at the alternator and run it to the + on the battery and see if that fixes it, you can always join the wire back up if it doesnt work, but i think it would definatly be worth a try.

corin

gfunkk Rising Star

gfunkk

Posted
Posted (edited)

Sorry to jim in but the other day at the track my voltage dropped from 13.6 to 11.8 and there was this whizzing sound coming from under my dash

I unplugged the box next to fuse panel that was making the noise and my rev needed went dead, the noise stopped but the volts didn’t change.. so i just plugged it back in

Then on the way home the volts slowly dropped to 11.1

So im replacing my alternator, hopefully that will fix this problem?

Edited by gfunkk
t_revz Grand Master

t_revz

Posted
Posted

i dont have the same model alternator as you but see if the thin wire to back of alternator has ignition 12v to it. if not there could be a prob with the excitation circuit depending on how that model works. you already he done alternator and doesnt sound like battery problem. if there is no power at back of alternator on the thin wire connect multimeter to battery of alternator circuit and quickly touch alternator + to thin wire terminal and see if it springs to life.

gfunkk Rising Star

gfunkk

Posted
Posted
Sorry to jim in but the other day at the track my voltage dropped from 13.6 to 11.8 and there was this whizzing sound coming from under my dash

I unplugged the box next to fuse panel that was making the noise and my rev needed went dead, the noise stopped but the volts didn’t change.. so i just plugged it back in

Then on the way home the volts slowly dropped to 11.1

So im replacing my alternator, hopefully that will fix this problem?

just an update if anyone cares, my voltage regulator was f'd

costed me $220 for a full rebuild

  • 5 weeks later...
scotty nm35 Grand Master

scotty nm35

Posted
Posted
Problem resolved. The wire from the alternator to the dash failed. Can't believe that's all it was. Cars working like a dream. Thanks everyone!

So they are the same design as VL, I couldnt believe the alternator stops working if the dash light circuit fails but thats the way it seems to be wired.

Does that mean if the dash bulb blows you're not charging?

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