Red battery light still illuminated after alternator change
Discussion
Red battery light came on on my 2011 1.2 SE on Sunday night, checked charge and when turned off the battery tested at 12.34v and when running it was at 11.83v.
Alternator was removed and reconditioned and fitted again this morning, when running its now at 14.2v however the red battery light is still on?
Has anyone else seen this issue?
Alternator was removed and reconditioned and fitted again this morning, when running its now at 14.2v however the red battery light is still on?
Has anyone else seen this issue?
A good alternator should give 13.5 to 14.5 when at idle, so that is ok.
As it hasn't had a good charge for a bit, give it a day or so & a good (20 min plus) run without much electrical drain & see how it is then.
It also could be (stupid though it sounds) that the car needs telling that it is getting a good charge, as in some cars need telling they have a new battery etc.
As it hasn't had a good charge for a bit, give it a day or so & a good (20 min plus) run without much electrical drain & see how it is then.
It also could be (stupid though it sounds) that the car needs telling that it is getting a good charge, as in some cars need telling they have a new battery etc.
Edited by E-bmw on Tuesday 21st March 15:26
The no charge warning light is usually triggered by a voltage difference between the ignition switched +ve and the the alternator +ve output. That means it can be triggered by the alternator output being lower than battery voltage (e.g. when the engine is stopped) but can also be triggered by the alternator output being higher than the ignition switched voltage (e.g. due to poor wiring allowing the ignition voltage to drop under load, or the alternator outputting an excessive voltage).
You should be able to check for both these conditions with a volt meter.
You should be able to check for both these conditions with a volt meter.
@greenv8s that's sounding a little out of my skill zone......
Just been back to the car in the hope that it had forgotten it had an issue, started it up and the battery light was not illuminated once the car was running, left it for a few mins and it came on, check the battery voltage and it was sat at 14.54 so exactly where it should be, checked with the car turned off and it's at 12.90 so again all appears correct, what I'm trying to get my head around is if the car is ok to drive or if the battery is going to fail at some point.
Cheers
Just been back to the car in the hope that it had forgotten it had an issue, started it up and the battery light was not illuminated once the car was running, left it for a few mins and it came on, check the battery voltage and it was sat at 14.54 so exactly where it should be, checked with the car turned off and it's at 12.90 so again all appears correct, what I'm trying to get my head around is if the car is ok to drive or if the battery is going to fail at some point.
Cheers
Assuming a normal alternator & not one of the ecu controlled variety (about which I know nothing) then I'd be interested to know just what the reconditioning was that it was given.
Changing a faulty regulator may well give you the increase in voltage you've seen but the common cause of the warning light coming on is a fault in the diode pack. Again, this is replaceable but as you still have wear in the bearings & the slip ring a fully reconditioned alternator might be the best bet.
I've recently had this issue with the A127 type fitted to my RRC with symptoms much the same as yours. Whilst those are simple enough to work on, the cost of an overhaul kit plus my time compared with the just over £50 for a replacement with warranty from a local reconditioners (Green's of Leicester for anyone local www.startermotorsleicester.co.uk ) who I've used for years made it a no-brainer. They ran mine up on their test rig whilst I watched & although it was charging fine the charge light was on. They do offer an on-car test but I forgot to ask what that cost.
Changing a faulty regulator may well give you the increase in voltage you've seen but the common cause of the warning light coming on is a fault in the diode pack. Again, this is replaceable but as you still have wear in the bearings & the slip ring a fully reconditioned alternator might be the best bet.
I've recently had this issue with the A127 type fitted to my RRC with symptoms much the same as yours. Whilst those are simple enough to work on, the cost of an overhaul kit plus my time compared with the just over £50 for a replacement with warranty from a local reconditioners (Green's of Leicester for anyone local www.startermotorsleicester.co.uk ) who I've used for years made it a no-brainer. They ran mine up on their test rig whilst I watched & although it was charging fine the charge light was on. They do offer an on-car test but I forgot to ask what that cost.
Edited by paintman on Wednesday 22 March 08:28
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