[Andyglynn]

Morning everyone.Hope someone can help me withthis odd problem,
When i turn the ignition to position 1 all the usual warning lights come on but the battery light goes out almost immediately before i crank the engine.When i drove home from work yesterday (about half an hour) and then tried the ignition, the battery light came on as usual and stayed on as normal.However this morinng i had the same thing with the battery light going out before starting.I fired the car up and drove a few yards and the battery light flickered a few times (witrh relay clicking sound).
The alternator is less than 3 years old and the heavy duty battery is less than 2 yars old.
The car cranks with good power so the battery seems to be ok.
Any ideas what might be the cause?

One thing to mention is that when i drive on wet roads the alternator light comes on for a short while before going out again.It has always done this.

I'd be grateful for any info.
Many thanks.

 

[g4vvq1983]

Hi Andy, strange one, i'm not 100% how that Alternator is wired, but here are a few pointers, do you have a Multi meter or voltmeter, if so put it on say a 20 volt scale and put it across the battery, without the engine running it should be minimum of 14.4 volts, with the engine is running it should be 13.9 to 14.7, that will tell you if its charging or not, Now i think your alternator has probably got 3 wires on, the big thick one goes straight to the battery positive terminal, make sure it's live all the time, there is prob a wire for the rev counter, goes from about 1 to 5 volts running, and there is a wire for the warning light, now the warning light wire normally either goes to the warning light bulb, or to a relay which turns the warning light off, usually under dash..the warning light wire on the alternator should have 12 to 14 volts on it running and 0 stationary, Make sure if the alternator is rubber mounted that it has a good earth on it, some of the vauxhalls have rubber mountings, and a big black earth wire, sometimes dont connect very well,..i suspect the fact the light comes on then goes of quick is a bulb or system test when you initially turn on...hope that is helpful....from Fred in Essex.

 

[Andyglynn]

Hi Fred.Many thanks for dropping me a reply.I do have a multimeter and will do the checks at lunctime.I recall when i had the new alternator the garage said it had to be the expensive one as it runs a vacuum pump or something.Odd that it should work noramlly when i'd driven it for half an hour then went back to going out again tis morning.I think i need to do allthe connection checks you suggested by getting it up on ramps in the morning and checking all the connections/mountings etc.a big squirt of WD40 a good idea as well? regards Andy

 

[g4vvq1983]

Hi Andy, yes sounds like a good idea, yep the Vacuum pump is because it is a diesel, and a diesel has little or no Vacuum in the inlet manifold to work the brake servo, or as the Americans call them, Brake booster...you can actually buy it without the pump from a factors and swop them over, cheaper that way...Fred in sunny Essex, at times, mostly raining.

 

[Andyglynn]

Hi Fred, ha ha yes raining here in Oxfod as well!
I have just been and put a multimeter across th battery (cold) and it read 11.58 volts.i started the engine (started well) and gradually the reading increased to 13.35 volts/ran it for 10 muntes and then turned it off and turned the ignition back on..alternator light went straight out again.i havent checked the alternator connections yet as it's out on the road and peeing it down.i'll leave that particular pleasure until tomorrow morning in the driveway.

 

[g4vvq1983]

Ok Andy it's still a bit low, one thing i should say, when the battery is down the alternator should throw a ton of current into it, at that point the voltage will be low, your supposed to check with amp meter on the battery lead as well, but i was assuming you don't have an amp meter, if not you have to have the battery voltage at least 12.4 volts to start with to get an accurate reading when it's running, you will need revs at least 2000 rpm to get charging reading right, 13.9 to 14.3, it sounds like its charging a bit but either not enough or intermittently...i do know with older systems the ignition warning light has to work or it wont charge, make sure the fans belts tight, ....sounds like your weather is worse than ours, i just has some turf put down in the garden and haven't had to water it yet..brilliant lol.

 

[Andyglynn]

Hi Fred,this little van has lawys had a fre foibles i nthe alternator dept.Thats why i ended up replacing the alternator, battery and starter motor a couple of years ago.i had a battery from a local factors as an urgent replacement and the garage said it was the battery and the factors said it was the alternator.In the end the garage insisted the new alternator they fitted was ok and i bought a new decent heavy duty battery from Hlafords.from that point everything was ok..happy days.!this alternator light has only started misbehaving this week when i'd driven to work on the A34 which had a lot of spray.The car starts fine o nthe battery even though it's sitting at 11.58 volts whenm cold.

thanks
Andy

 

[g4vvq1983]

Hi Andy i was having a look at the charging system on a wiring diagram last night, on my car there appears to be 2 wires, one goes straight to the battery, thick red one, and a blue and white for the warning light, goes from the alternator to the Multifuntion Module, fron there it goes to dash light etc, so it's not a straight forward circuit, but i would stick to basics if you can...Fred.

 

[g4vvq1983]

Hi Andy. on the first message above it should read when the engine is stationary the battery should read a minimum of 12.4 not 14.4 too may late nights....Fred.

 

[Warabile]

Hi I've got a problem of my alternator my battery light doesn't come on in the dashboard on corsa lite 1.4 engine.so my alternator doesn't charging my battery because when I remove terminal the car cut off what is the problem