Strange charging problem
Discussion
Help - the battery light keeps on coming on as I am driving and then going off again for no apparent reason. The voltmeter also drops down at the same time.
It comes on as normal when I first start the engine and goes off again once the rpm rises above 2000 so that at least is normal.
It can happen whilst I'm hooning it down the road or sitting at idle in the traffic. And then it will go off again and the volts will rise back up. So something is wrong with the charging system but I don't know what.
It appears that I can make the light go off again by really revving the engine (5000rpm+) and then letting off the throttle but I'm not sure if that is just coincidence as it will also turn off and start charging again without me doing anything.
I have tried wiggling the wires on the alternator whilst on the drive to see if maybe there is a loose connection or something but I can't get it to do it to order.
The alternator is fairly new (approx 12 months) so I hope it's not that. I've checked the wires to the alternator and they are all firm and clean. I don't think the belt is slipping as I can't hear it and it doesn't get worse or better when there is a high load on like the headlights.
Could the diode pack be on it's way out?
Anything else I can check?
Thanks
It comes on as normal when I first start the engine and goes off again once the rpm rises above 2000 so that at least is normal.
It can happen whilst I'm hooning it down the road or sitting at idle in the traffic. And then it will go off again and the volts will rise back up. So something is wrong with the charging system but I don't know what.
It appears that I can make the light go off again by really revving the engine (5000rpm+) and then letting off the throttle but I'm not sure if that is just coincidence as it will also turn off and start charging again without me doing anything.
I have tried wiggling the wires on the alternator whilst on the drive to see if maybe there is a loose connection or something but I can't get it to do it to order.
The alternator is fairly new (approx 12 months) so I hope it's not that. I've checked the wires to the alternator and they are all firm and clean. I don't think the belt is slipping as I can't hear it and it doesn't get worse or better when there is a high load on like the headlights.
Could the diode pack be on it's way out?
Anything else I can check?
Thanks
I had a similar problem to yours and in the end took the car to Lucas to sort out.
What they found was a break in the smaller wire that comes off the back of the Alternator, they repaired/replaced it and everything is now fine.
This wire apparently goes to the Voltmeter which in turn operates the diode bulb on the Battery logo,the voltmeter would previously stay way down at the bottom of the gauge until the engine was reved hard and then it would settle up at the normal charge position.
Hope this helps.
What they found was a break in the smaller wire that comes off the back of the Alternator, they repaired/replaced it and everything is now fine.
This wire apparently goes to the Voltmeter which in turn operates the diode bulb on the Battery logo,the voltmeter would previously stay way down at the bottom of the gauge until the engine was reved hard and then it would settle up at the normal charge position.
Hope this helps.
The Alternator I was told rarely in its self fails but if you do have to get it checked, take it to the garage with it fitted in the car.
Trying myself earlier to resolve the problem I found the Brushes on the Alternator(on a plate at the back) were sticking and not charging until they "unstuck", hence at times on a short run no charge was going to the battery and you were continually discharging it, hence the Voltmeter would show low and then suddenly spring back to life - again may be worth checking your brushes.
Replacement brushes on mine were £23 (fitted myself) and I believe an exchange Alternator (supplied only) was about £58.
Trying myself earlier to resolve the problem I found the Brushes on the Alternator(on a plate at the back) were sticking and not charging until they "unstuck", hence at times on a short run no charge was going to the battery and you were continually discharging it, hence the Voltmeter would show low and then suddenly spring back to life - again may be worth checking your brushes.
Replacement brushes on mine were £23 (fitted myself) and I believe an exchange Alternator (supplied only) was about £58.
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