Hi guys been out in the 5today running a afr gauge off the fag lighter,anyway whilst using the battery light came on.the battery had drained.took the gauge out and drove about. 7 mile home with the light still on.when I got home there was no power in the battery.thanks
Just been out and the car started but the battery light is still on.
You need an amp reader to see if the alternators nackerd bud
Just had the battery and alternator checked at halfords.The battery was ok but the alternator according to the printout,regulator volt low.Is there anything else worth checking or should I just get a new one.thanks
You could check your alternator and battery wiring/connections are all good. In fairness when I had an alternator go it was exactly the same symptoms. Driving along and the light came on and stayed on.
The light every now and then will flicker,don't no if that makes any difference.
Could be a bad earth connection ...... Check the wires from the -ve on the alternator and follow round .... I think 1 lot attaches on block .
That's not a battery light, it's an alternator light. It's fed from one of the two wires at the top of the alternator. It's job is to tell you the alternator is not working.
You need a voltmeter.
Put it across the battery terminals with the engine running it should be about 13.6V.
If 12V or less, the alternator is not working. Or the feed wire is not connected. You can put the voltmeter across the alternators big (red?) wire and an earth to see if it's 13.6V.
There are many causes for the alternator not working. Could be wiring connections corroded or lose or it's Regulator, that maybe a spare part on it's own and cheaper than the whole alternator.
I got 12.37 with the meter on the battery.
With the engine running? I think that will just be the battery voltage.
Is it less with the engine off?
Sorry yeah,its the battery voltage.going to get a volt meter tomorrow.All I no at the moment is the battery is not receiving enough volts to charge it properly.Just put the headlights on whilst on idle and then the indicators. No dimming and engine revs stayed the same.while having yet another look IV noticed a brown and white wire that are connected to what looks like a brass bung with a white plastic top hanging loose resting on the gearbox/block.any ideas.
Last edited by casper; 01-09-2012 at 19:56. Reason: more info
check the alternator is earthed properely.
Doesn't the alternator earth via the nuts and bolts of the bracketry? No earth wire. The earth wire is from the engine block to the chassis then to the battery.
You can use the multimeter again, but set to continuity or Ω. Measure between the alternator metal body and the battery earth terminal. Should read near to zero Ω or continuous beep.
DON'T TOUCH THE BATTERY +VE in continuity or Ω OR THE METER WILL LIKELY BE DAMAGED.
Alternator is rubber mounted on the bracket and the tightening arm.
Don't no if this helps but there's currently no heat shields in place,its the anti perc fan sensor off the Turbo heat shield that's hanging down.I'm a bit thick when it comes to Electrics so if someone could explain what I put where regarding volt meter and alternator just so I can either eliminate it or replace it.Trying to think of anything now and the other day I replaced the dials with the ones out of the shop,and wasn't 100percent sure I had got the smallest connector the one with the two wires the right way round.Probably nothing as it worked untilled today
Last edited by casper; 01-09-2012 at 23:13. Reason: described
Is the alternator metal body at earth potential? I've apparently forgotten. Not seen one for 5 years or so.Originally Posted by Tony Walker
Are it's wires melted? I no longer know what effect that would have.
Try as I said a couple of posts up but measure between the engine block or head and the battery negative. That will at least check if those two earths are OK or not.
I have had the multimeter on the 5 this morning,with the engine off the battery volts were 12.4 with the engine on idle the figure was the same.I took a reading from the live on the alternator earthed to the block and that was 12.2.I then pulled the brown connector apart and took a reading from the yellow wire and that was -0.04.what does this tell me.
Ian I did what you said and got 0.06.The battery dosent seem to be draining as I have been out in it and its still 12.4.On idle it drops to about 12 ish. The alternator positive is also 12 ish.The yellow wire at the top is not outputting 12v.Is it that the battery is charging just not enough,should I just get a new alternator.
Alternator
Sorry for not replying sooner.
I've forgotten what the two wires at the top are doing, apart from one to the warning bulb.
Sounds like the earth straps are OK. The +12 on the alternator live could be from teh battery.
So yes I agree that throwing on a replacement alternator is the next thing. Unless you can get a regulator on it's own for a worth while saving. However if the bearings on the alternator are a bit worn or stiff then it's best to change the whole thing.
the alt onlyworks if the yellow wire has 12v as in battery voltage if the yellow wire reads 0v. thats why the alt is not working
Yellow wire has 12v.
Well I put mi new alternator on today,started the car with a bit of choke and get in there,the warning light went off.Let her warm up for a bit and then took the choke off and the light came on.bollocks.put mi meter on the battery on idle 11.8v.Increased the idle speed to? ????? Not sure cos rev counter has packed in but seems high and the lights gone off.
try a set of jump leads on the alternator where you tighten the bracket then the earth on the battery then measure your battery voltage.
(thats just the one lead no need to connect the positive anywhere)
I'm proper confused now.the old alternator had the light on all the time no matter what I did.This new one has the light off at above normal idle speed but still dosent appear to be charging the battery.
do you have spade connectors on the top of the alty or the original connector?
Spades inside original brown connector.
I'm just wondering,my battery has less than 12v in it,would that have an effect regarding the yellow feed wire.
If your still having problems and you've replaced the alternator you need to take a look at the connector of death.. This is located under the header tank, it's black in colour.
Put some new spade ends on.problem solved!!thanks to everyone who tried to help.
Glad you got this sorted
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