Alternator question

[john2k]

I purchased a brand new aftermarket Alternator for my car. It's unbranded but the label of the model number seems to suggest it's a Lucas Electrical alternator.

I have a question for someone who knows about alternators. I unpacked the new alternator and externally looks good build quality. I decided to spin the pulley by hand back and forth which was fine. But at one point there was some sort of resistance when I was spinning it almost like it's getting stuck on something but it wasnt strong resistance as I just gave it a harder spin and it carried on spinning but it was doing this resistance thing for a few spins but then after a few spins it stopped doing it and is freely spinning again. I'm just wondering if this is something to worry about ? Should a brand new alternator have something like this?

 

[Burnerman]

I can't see any reason for an alternator to have any tight spots.....certainly when spun by hand anyway, different with electrical connections in place!
The stiffness can only really come from the two bearings that support the commutator and the only other things in contact are the small carbon brushes rubbing on the slip ring at the back.
Is this device a brand new or reconditioned item?
John

 

[john2k]

Is this device a brand new or reconditioned item?

It's supposed to be brand new and looks brand new.

 

[Burnerman]

It will have a twelve month warranty anyway so if it seems ok I'd go ahead and fit it, listening for any odd noises.
The Lucas ACR was renowned for a whining noise when under load and the cut in speed (when it starts to charge) is around the 1000 RPM mark if I recall.
John

 

[john2k]

Yeh it does come with the 12 months warranty. Strange thing is it did it that one time and after that I haven't been able to recreate the resistance. I may have had the alternator tilted but that shouldn't really cause it though should it?

That's a bit worrying about the Lucas Alternators being known to whine and cut out. What happens if an alternative cuts out or pulley seizes? I assume seeing as it's a V ribbed belt the belt should still be able to spin? Or will it still the engine?

 

[Burnerman]

Maybe the alternator has been sitting on the shelf for a good while- I don't know but if it's ok now I'd forget about it. Tilting has no effect.
Whining is a characteristic of the ACR and means nothing, and alternators don't seize.....the bearings may rumble after a high mileage of course. If the alternator did lock up the belt would burn and be thrown off in no time.
John

 

[ericmark]

Bit of cardboard fallen off box in the alternator maybe? There were a few variations of the Lucas ACR alternator, and at one time I reconditioned 100's. The method was to completely strip them, bead blast the case, slightly anodise them, then rebuild, where I worked always new bearings, but not all people did that, and also watched the output on an oscilloscope which would highlight any regulator problems, always new brushes, and would not reuse Lucas rectifiers but would reuse Durite rectifiers as far better quality to Lucas. And when you looked at our reconditioned alternator it was hard to see it was not new. I could do around 25 a day with other duties as well.

We had a deal with scrap yard, they sold alternators off scrap cars as part x, and we bought the faulty alternators off him.

 

[john2k]

So i installed the new alternator, it was a very awkward and tight place getting it out and in. When you look through the vents, what are the copper/bronze looking coils like the ones arrowed in pic below? While trying to get the new alternator into its position through the tight opening one bolt managed to catch a little into that slot and made a ever so slight scratch on that orange/bronze looking coil. The scratched area looks a bit silver. Is this a major problem?

 

[Burnerman]

You've scratched off the varnish from one of the stator coil windings....from what I can see you've done no harm.
Are you aware that the alternator has a sliding metal bush on one end of the bracket which adjusts when you tighten the bolts - for ease of fitting?
John

 

[john2k]

You've scratched off the varnish from one of the stator coil windings....

So the coils are coated in some kind of colour? What happens if one of these coils were to like get more deeper damage?

Are you aware that the alternator has a sliding metal bush on one end of the bracket which adjusts when you tighten the bolts - for ease of fitting?

Ahh is that why when I was tightening the top bolt it looked like the bolt was tight but it kept going almost like something is springing and then eventually it tightened.

 

[Burnerman]

The coils will be copper, maybe with some kind of coating and then they are dipped in varnish to give them weather protection.
So long as several of the coils haven't been mashed and are cross connecting - no evidence of this - then all will be well. You could give it a dab of varnish if you feel so inclined!
The bracket is solid at the pulley end with the sliding bush - usually tight as hell - at the other. The solid end is tightened first and then the sliding bush adjusts itself.
Tip of the week - don't run the alternator without the car battery connected....it will goose itself so make sure all connections are done before starting up.
John

 

[john2k]

OK so a disaster, i installed the alternator and when I started the car, the alternator was whining so loud went to check it and a huge amount of smoke was coming out of it. Litterally smoking bad. So I turned off the car and disconnected negative again. Does that mean a bad alternator? I installed it all properly, the only thing is the little scratch on the coil that I posted about earlier but surely a scratch to the coil shoud't cause this?

 

[Mottie]

Does that mean a bad alternator?

Yep. Take it back.

 

[john2k]

Yep. Take it back.

Really annoyed as it was quite a lot of work getting that bugger installed. Have initiated a return request. Surprised that a so-called brand new product can do this. Is there anything I could have done wrong in the install that can cause this? like I mentioned, the only thing I did was accidently get a bolt caught in that vent area and it scratched one of the coil a very little but looks like just scratch on the varnish.

Also, I did replace the idler pulley as old one was a bit noisy and replaced belt with new OEM belt. But I did spin the idler pulley by hand me it was spinning freely so I don't think idler pulley caused it

 

[Burnerman]

Hells bells
For sure I can’t see any significant damage that you have done from your photo.
I would, however double check the suitability of the replacement for your car.
Tell us more about what you are doing, please? Are you replacing the alternator because of a dynamo conversion, has there been a change in polarity or direction of rotation?
John