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alternator works sometimes
Posted: Thu Oct 29, 2009 4:43 pm
by r055
My alternator was replaced last year under AA parts and Labour (just over a year ago) and it seems to be fecked again.
When car is started from cold, the battery light remains constantly lit and all power is from battery.
It eventually flickers and goes off once the temp is up at around 60deg.
Once up at the right operating temperature, I'll not see the light come on until I leave the car until it goes cold again.
The belt has been checked and is fine.
does this sound like a new alternator is required or something to do with the excitor circuit? would that relate to the temperature? soldering?
Ross
Re: alternator works sometimes
Posted: Thu Oct 29, 2009 4:52 pm
by roadboy
Sounds like a faulty regulator on the alternator. As far as I know, they aren't available seperately so it would be a new alternator.
Has the charging rate been checked when it has faulted?
Dan
Re: alternator works sometimes
Posted: Thu Oct 29, 2009 5:06 pm
by r055
roadboy wrote:Sounds like a faulty regulator on the alternator. As far as I know, they aren't available seperately so it would be a new alternator.
Has the charging rate been checked when it has faulted?
Dan
hi Dan,
I sat with meter on it when it was running on fault and when the light flicked off.
There was no difference in Volts from when the engine was running to when it was not.
Then the charge kicked in when it had been sitting for a while.
R
EDIT to add: is this not the regulator?
http://www.woodauto.com/Component.aspx?Ref=VRG46446
Re: alternator works sometimes
Posted: Fri Oct 30, 2009 11:12 am
by whaleys
r055 wrote:roadboy wrote:Sounds like a faulty regulator on the alternator. As far as I know, they aren't available seperately so it would be a new alternator.
Has the charging rate been checked when it has faulted?
Dan
hi Dan,
I sat with meter on it when it was running on fault and when the light flicked off.
There was no difference in Volts from when the engine was running to when it was not.
Then the charge kicked in when it had been sitting for a while.
R
EDIT to add: is this not the regulator?
http://www.woodauto.com/Component.aspx?Ref=VRG46446
That's the regulator for an S2 K-Series alternator not sure if it's different for the S1 though. I had similar issues and with a lot of help from Robin and others, I replaced the regulator and it was great for about 3 months until it happened again. I had it bench tested and it was confirmed the regulator had gone again. As the regulators for these alternators are quite expensive, instead of fitting another, I opted for a new alternator from Woodauto. Been fine for a year now.
Just something to bare in mind, sometimes trying to save money ends up costing you more (unless you are really good with these things
).
Graeme
Re: alternator works sometimes
Posted: Fri Oct 30, 2009 12:24 pm
by roadboy
If there was no difference in voltage when the engine is running and not then the alternator is not working. Not sure why the charge light isn't on if its not charging.
What voltage was it reading?
Dan
Re: alternator works sometimes
Posted: Fri Oct 30, 2009 12:32 pm
by fd
roadboy wrote:If there was no difference in voltage when the engine is running and not then the alternator is not working. Not sure why the charge light isn't on if its not charging.
Because the enable wire (small one) to the alternator is not connected, ie. bad connection, and a notorious cause of damaged alternators it seems . . . The alt grounds this wire when it's not producing charge hence lighting the light and raises it to charge voltage when it is producing charge, also without some current supply from this wire into the alt the alt will not power up . . .
I'd check/replace the wiring loom for that cable, it not an uncommon failure.
Assuming K series . . .
Fd