Do I need a new alternator?

R

richarduk

Guest
On the way home last night the alternator light came on. Odd but it seemed to get brighter the more revs, always though it would be the other way round. Anyway got home fine even thought the lights were on. Just tried her this morning and she fired up fine, I had expected after a 25min drive with no apparent charging with lights on that she would not have started. Also when the engine is running I can disconnect the battery and she still runs, did stop the moment I put the lights on.

Is there any other part I should check before getting a new alternator? The one on there does not look that old.
 
richarduk said:
On the way home last night the alternator light came on. Odd but it seemed to get brighter the more revs, always though it would be the other way round. Anyway got home fine even thought the lights were on. Just tried her this morning and she fired up fine, I had expected after a 25min drive with no apparent charging with lights on that she would not have started. Also when the engine is running I can disconnect the battery and she still runs, did stop the moment I put the lights on.

Is there any other part I should check before getting a new alternator? The one on there does not look that old.
Click to expand...

Turn the ignition on but do not start the car.

Is the alternator light on when you do this?
 
richarduk said:
Also when the engine is running I can disconnect the battery and she still runs, did stop the moment I put the lights on.
Click to expand...

I thought that this was strictly prohibited with alternators!

richarduk said:
Is there any other part I should check before getting a new alternator? The one on there does not look that old.
Click to expand...

It should be a Lucas 16 ACR right? You'd better have someone connect an ammeter (or a voltmeter could do the job) and really see if it charges or not.
Usually it is the rectifier pack under the plastic cover at the back that goes wrong. You just replace it with a new one, renew bearings, brushes and contact ring for good measure since you have it apart, and you 're done. There 's no need to spend on a new alternator!
 
quattro said:
richarduk said:
On the way home last night the alternator light came on. Odd but it seemed to get brighter the more revs, always though it would be the other way round. Anyway got home fine even thought the lights were on. Just tried her this morning and she fired up fine, I had expected after a 25min drive with no apparent charging with lights on that she would not have started. Also when the engine is running I can disconnect the battery and she still runs, did stop the moment I put the lights on.

Is there any other part I should check before getting a new alternator? The one on there does not look that old.
Click to expand...

Turn the ignition on but do not start the car.

Is the alternator light on when you do this?
Click to expand...

Yup. Then when it starts at low revs, tick over it's faint, higher revs it gets brighter, which is odd. On other old cars I've had that have needed a new alternator it's been the other way round.
 
Demetris said:
richarduk said:
Also when the engine is running I can disconnect the battery and she still runs, did stop the moment I put the lights on.
Click to expand...
I thought that this was strictly prohibited with alternators!
Click to expand...
Nope, not a problem, maybe it's with dynamos.
 
Demetris said:
It should be a Lucas 16 ACR right? You'd better have someone connect an ammeter (or a voltmeter could do the job) and really see if it charges or not.
Usually it is the rectifier pack under the plastic cover at the back that goes wrong. You just replace it with a new one, renew bearings, brushes and contact ring for good measure since you have it apart, and you 're done. There 's no need to spend on a new alternator!
Click to expand...

Looks like it should be a 16 ACR, I'll take it of to make sure. There is a Lucas main dealer in town so they should be able to referb it or at least help me out. Just wanted to make sure if the P6 electrical system had any other bits that I would need to check that could cause this.
 
Just taken it off, can't tell what one it is. The only label is a bit faint, it's got 12V and LAA on its. Getting a closer look at it it's seen better days.
 
All fixed. :) Got a kit from eBay for £15 inc postage. Ordered it yesterday came to day, two hours later (the soldering is a bit awkward) car running sweet again! :)

I'll post it up on my blog later, with pictures. :)

I don't think I'll ever buy a recon alternator again, £15 or £85????

I'm quite proud of my self. 8)
 
richarduk said:
All fixed. :)
I don't think I'll ever buy a recon alternator again, £15 or £85????
Click to expand...

Don't blame you, even for £85 (or howevermuch) you're unlikely to get one fitted with the new parts you bought. Mostly they just get dismantled each individual part gets tested and then all the good secondhand bits get reassembled into "recon" units, with new brushes if you're lucky.
 
I hadn't realised that you'd bought the parts from JCRSupplies. They're close to me and are a great little outfit that are a pleasure to deal with, whether over the internet, or in person in the shop. The place is packed to the rafters with all those kinds of electrical bits that you just can't seem to get anywhere else these days. Highly recommended. (And I have no connection with them other than as a very satisfied customer over a good few years now.)
 
Re: Do I need a new alternator? - Thanks Richard

Thanks for your efforts with the post and photos Richard - I too saved money from buying the rectification kit.

Its people like you who put the time and effort into helping others that keep these cars on the road by making them affordable.

Cheers
Eggbert68
 
Re: Do I need a new alternator? - Thanks Richard

eggbert68b said:
Thanks for your efforts with the post and photos Richard - I too saved money from buying the rectification kit.

Its people like you who put the time and effort into helping others that keep these cars on the road by making them affordable.

Cheers
Eggbert68
Click to expand...

Very nice of you to say sir. My little way of repaying the loads of help i've had keeping the Soup Draggon on the road. This forum is indespensible! :D
 
You must log in or register to reply here.
Back
Top