Alternator fault

[phil clark]

Hi. Has Anyone ever experienced this type of fault before.
For about the last five days, everytime ive started me hdi, the battery light has been illuminated. After a light blip on the pedal, it goes off, and stays off. Today things changed, because It wouldn't start, as the battery was flat, so jump started it, and tested across the battery. Sometimes the reading was 12.2 volts, then 13.4, then 12.6, up and down, but still no battery light after the blip. Took the alternator off, stripped the back off, and cleaned it with contact spray. 3 mths ago id changed the brush pack as they were worn badley, and everythings worked great up until now.
Any ideas guys, and could it be an earthing fault. Many thanks

[Poodle]

Worth checking your earths certainly, but sounds more like an issue with the reg or exciter.

[phil clark]

Worth checking your earths certainly, but sounds more like an issue with the reg or exciter.

Cheers poodle.
Now this is where I become a little confused.com lol. In your post bud, you spoke of Regulator or Exciter, and to me that sounds like two separate things, yet in the Alternator its just one thing, the part which the brushes attach too (Y/N ???)

I changed that two mths back for a new one and everything worked fine, But im now beginning to think that I may of (by mistake) poured water/antifreeze into the poor thing, due no less to the expansion tank location.

Im considering changing the whole unit now, for a tested used unit, from a Peugeot breaker, as the £165 cost of a Reconn is well above my current means.

What do you think, worth messing about with???.

Thanks

[Poodle]

Oh is it? I've never had an alternator apart myself, didn't see the point when you can pick up working units second-hand for ~£20 lol. Just going from what i know of the theory tbh. I would assume that's the part the brushes are connected to, as that's being the part that transfers out usable power supply.

Sounds like you've already replaced a lot of the alternator's working parts, could it just be that the remaining parts are worn to an extent they no longer work properly, damaged coils etc..?

[phil clark]

Oh is it? I've never had an alternator apart myself, didn't see the point when you can pick up working units second-hand for ~£20 lol. Just going from what i know of the theory tbh. I would assume that's the part the brushes are connected to, as that's being the part that transfers out usable power supply.

Sounds like you've already replaced a lot of the alternator's working parts, could it just be that the remaining parts are worn to an extent they no longer work properly, damaged coils etc..?

No doubt bud, no doubt. Well, what a game ive had today lol. Went to the Peugeot breakers, and out of well over 100 cars, I simply couldn't find one. There was Everything else but lol, so ive had to resort to getting a CL15 (official valeo type) off Ebay. Our French friends certainly liked to keep the Ancilary Designers busy, back in the day. Thanks for sound advice ;-)

[Poodle]

Not sure if serious...

Bugger about the alternator, at least its fixed for the foreseeable life of the car.

[Ruan]

I suspect that will have been the regulator pack on the back dying...

The whole not doing anything, but when you rev it the light goes out - that's the alternator self exciting as the residual magnetic field isn't strong enough to induce enough of a current in the field windings to start generating.

That's why you have the exciter (small) wire on the back of the alternator - this is what excites the alternator normally, that is applied to the field windings which then generates a strong current to start it generating.

But generally, if you've replaced the brushes, regulator - the bearings are probably on their way out, you'd end up in the good old broom with 3 new heads and 2 new handles situation before long!!!