Alternator not Charging, but No Warning Light
Discussion
my Alternator's not charging, but neither is my warning light on the dash illuminated to tell me as much
..which makes me wonder if its the Alternator at all
I'm aware that the Alternator receives a signal via an LT feed, from the Ignition; is there some way I can check this feed before I potentially waste a couple of hours or more changing it
....I have just 12.5V at the Battery with the engine running and giving it a rev makes not a jot of difference
Car is old enough to be 'pre-ECU', so old school rules apply, an N reg Pug 405, Diesel
Said Warning Light is operating as normal
..which makes me wonder if its the Alternator at all
I'm aware that the Alternator receives a signal via an LT feed, from the Ignition; is there some way I can check this feed before I potentially waste a couple of hours or more changing it
....I have just 12.5V at the Battery with the engine running and giving it a rev makes not a jot of difference
Car is old enough to be 'pre-ECU', so old school rules apply, an N reg Pug 405, Diesel
Said Warning Light is operating as normal
Thanks Guys, tested as suggested including with regard to shorting the thin lead to Earth (just ring connectors for me, not even a multi-plug), no warning light with it disconnected and warning light nice n bright with it going to Earth (see pic, Moley'd to Alternator fitting)
...so all seems fine, albeit would be nice if the Warning Light 'd warn me of 'No Charge' like its sposed to (I'd intended running it with the Aux Belt off, to see if this'd prompt a warning light but forgot)
Also remembered that giving it a whack can re-instate operation briefly and this further proved that the Alt was indeed duff.
Changed for a good 'un and sorted, will hang onto the old one in case I can ever be bothered to change the Brushes and research getting the Slip-Ring sorted; did once rebuild one of these, years ago, but it was a very short-lived fix, as it turned out the Slip Ring was kaput as well as the Brushes.
FYI only. Thanks again
...so all seems fine, albeit would be nice if the Warning Light 'd warn me of 'No Charge' like its sposed to (I'd intended running it with the Aux Belt off, to see if this'd prompt a warning light but forgot)
Also remembered that giving it a whack can re-instate operation briefly and this further proved that the Alt was indeed duff.
Changed for a good 'un and sorted, will hang onto the old one in case I can ever be bothered to change the Brushes and research getting the Slip-Ring sorted; did once rebuild one of these, years ago, but it was a very short-lived fix, as it turned out the Slip Ring was kaput as well as the Brushes.
FYI only. Thanks again
Did you remove the regulator/brush-box from the replacement to check the brushes and slip-ring
There is a design fault with the alternator mounting position, the regulator/brush-box is in the wrong position, it's at the bottom of the alternator. As the brushes wear the particles off them drop down into the brush holders and eventually the brushes stick, brushes no longer have the spring pressure
There is a design fault with the alternator mounting position, the regulator/brush-box is in the wrong position, it's at the bottom of the alternator. As the brushes wear the particles off them drop down into the brush holders and eventually the brushes stick, brushes no longer have the spring pressure
no, I haven't bothered yet Penelope, but I'll keep that in mind if/when I do, thank you. I just swapped it with one of my three spares.
If I get a quiet moment sometime I'll strip it down and see whether I feel its a candidate for refurbishment or the scrap man, but the 'big plan' at the moment is preparation and practice for some serious welding, next Spring / Summer; which includes stripping down a huge section of Donor panel that I spent two days removing in a scrappies, just before lock-down.
At least it didn't go miles from home, we've got a long-ish journey coming up... and the last time I had an Alternator failure was, memorably, in Germany !
If I get a quiet moment sometime I'll strip it down and see whether I feel its a candidate for refurbishment or the scrap man, but the 'big plan' at the moment is preparation and practice for some serious welding, next Spring / Summer; which includes stripping down a huge section of Donor panel that I spent two days removing in a scrappies, just before lock-down.
At least it didn't go miles from home, we've got a long-ish journey coming up... and the last time I had an Alternator failure was, memorably, in Germany !
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