possible alternator issue

[strongtom]

Hi all,

My battery warning light is intermittently going on and off, having searched the sight (and from a past alternator failure on a holiday, great fun!) I predict that the alternator is on its way out, the other problem which would be nice is the wiring to the warning bulb, unfortunately I'm finding it hard to test the alternator because its not illuminated at the moment, if like Ade, in this thread;

http://www.volvo-480-europe.org/forum/v ... ng#p198980

-I knew what all that stuff meant I'd try that but I don't, so any bright ideas? or does anyone have a spare for sale? Any suggestions would be very much appreciated, generally I try to do the cheap option but just need to keep the car going especially with some big drives coming up.

Best
Tom

[Espada]

If you have a multimeter start by testing what you know to prove it is ok.
Lets for now ignore the alternator and try to prove the charge light.

No charge light with ignition on and engine not running.

On the alternator there is a small red and brown cable, this supplies 12volts to the alternator.
Remove this cable from the alternator and connect it to the possitive lead on your multimeter
Then connect the negative lead of the multimeter to a suitable earth point.
Turn on the ignition DO not start the engine. Does the voltage meter read 12 volts or there abouts.
If it does this suggests that the charge light circuit is ok and points towards the alternator.

Replace the red and brown cable on the alternator.

If you did not get a reading then try the charge light bulb.

Take a note which bulb you are trying to remove and then reach in from the footwell and try to remove the charge light bulb. It might simply have blown or have a poor connection to the instrument panel removing it and replacing it will clean up the connection. However I know access is tight, I have done it so it might be an idea to get a replacement first as then you will know that the bulb will be good.

After trying this do things work as they should?

Next will be the alternator but checking the above will confirm that everything else should be ok.

Regards

[Espada]

Post removed so not to confuse things.

[glasgowjim]

+Dead simple way to check alternator there is a small screwed down wire onto the alternator loosen it and get some one to move it as the engine is running you should see the light glow dimly as the contact is waggled and a poor connection is made. If that happens then yes your warning light is ok .

Usually 9 times out of ten its the regulater , the brushes wear down and need replaced which is cheaper than a new alternator.

Keep an eye out for either Aldi or Lidl 's car offers and buy a battery / alternator tester (one unit) for about a £5 with change.

I did and it has proved invaluable , dont use it often but when you do its a life saver.

[AcidicDavey]

I have a bugger of an electrical issue at the moment.

The voltometer needle wiggles about like anything, infact...
http://www.youtube.com/watch?v=M5OHE6nm ... Ojmh80BUFw

Also the lights flicker and the engine looses its' smoothness obviously.

Any ideas?

The battery connections are fine btw.

[strongtom]

Wow, thanks for all the advice, I will get started tomorrow and report back, should I test regardless of the light being on or take it out for a while until it comes on and check then, I'll probably do both, I don't think it's a problem with the bulb but I can change it anyway, would be worse if it was the srs bulb or one on the top row but I can get to that one without removing the dash, again!

Thanks once more
Tom

[Espada]

Yes even with no charge light test regardless.

Good idea Glasgowjim as this method is free and can be done without the multimeter.

Regards

[strongtom]

Right; checked the charge bulb and wiring, all seemed ok the checks suggested that the circuitry was ok, so decided to go balls deep and remove the alternator, not such a big task actually, took of the regulator and the brushes do look quite warn, one (the outer one) much more so than the other, do they start at different lengths or does one just tend to wear down quicker?

Next thing is to find a new regulator, it doesn't look like I can just change the brushes unless someone can tell me otherwise??? Is this something I would be able to pick up from my local parts dealer or volvo specialist? or do I need a delivery from Glasgow???

Cheers
Tom

[Espada]

The brushes start off at the same size but without looking, yes if they have worn at different lengths then it does suggest it has worn out, this is certainly the next thing to do.

For refernence the minimum brush lengths for the Paris Rhone alternator are 8mm and for the Bosch and Valeo its 7mm. This length is the visible part that you can see.

Depending on the ability of your local motor factors they should sell them, though most these days concentrate on air fresheners etc.

So failing this, try a google search for your type of alterantor for the voltage regulator, you will be able to get them.

Regards

[strongtom]

OK here's an update,

I ran down to my local Volvo specialist who pulled a regulator off an alternator (don't know what from) and just gave it to me to try out (thanks P&R cars ), fitted it (after a little modification, had to drill out a bit of the mounting for the existing bolts to fit) and put the alternator back in the car.

Recap of initial problem; Battery warning light was coming on after a while on a long-ish drive (60 miles), went off and on a bit, I think hitting a strategic pot-hole switched it off. checked the wiring to the light and the bulb itself, no problem then changed the regulator as above.

Now; set off on the same journey happily with no light, then after 15-20 miles as before the light came on again, this time though it was dim and then went off and stayed off, I have then done the same journey three more times and the light was coming on much as it did in the first place along with, in the last of the three trips, a few other electrical fun times; rev counter did a little jesus trick and die then come back to life, and at one point it all went off and came back on.

I think its screaming dodgy earth but which one and where or are there any other ideas. Oh one other thing the vault meter (in the car) read all they way up at 16 when the new regulator was fitted and the settled back to what it was before which is just a little under 16 and when the charge warning light came on it did fall in response.

Thanks in advance for any of your thoughts and for those already posted.

Tom

[Espada]

Dodgy earth possible but as you say if you are thinking, on the dashboard where is it?

16v on the charging is high, though as long as this settles down to nearer 13 to 14v it should be ok.

in order to try and eliminate the earth theory if you have a multimeter, with the engine running set it to volts and connect the possative and negative leads to the same terminals on the battery and see what it reads. If the readings there abouts match the gauge on the dashboard, this in theory eliminates an earth with the gauges or in the dashboard, or at least confirms that the volt meter on the dash is not giving false readings.

You are looking for around 13.4 to 14.4 volts steady, but dont quote me, at least this will confirm that the alternator is charging.

As to the gauges going scatty assuming that the alternator is now charging are there other issues like the battery itself, is it accepting a charge and are all the connections good. Did it die when you changed gear as in you dipped the clutch, the revs dropped and there was little charge in the battery.

I know you know the answer, its check all of the obvious. But first try the above to at least prove the alternator is working.

If I have a sudden burst of insperation I will let you know.

Regards

[glasgowjim]

the earth points under the dash assuming a right hand drive car are to be found up in the top right hand corner below the dashboard . It is a copper square turret shaped piece of metal about 2 to 3cm tall.

[volvorich]

Hi all.
I have just had a similar experience - my battery light was flashing now and again, with no real consistency that may offer any clues. I checked the output voltage of the alternator and had the battery load tested - no issues, but still the intermittent battery light flash. My voltmeter in the dash would dip on a particularly strong bout of battery light flashing, but all seemed to return to normal until the meter showed a distinct lack of charge - down to about 9 volts or so.
The alternator was clearly not charging at that time, so I popped the bonnet and wiggled the wires. This created a few sparks and the main power cable came off in my hand.
It turned out that the thick red cable had corroded and was only being held onto the alternator by a few strands of 24 year old copper.
Luckily I had enough battery power to get to Sheffield & Meredith in Leicester where the wonderful chap there crimped a new ring terminal on it for me. Since then...touch wood...it's been fine.

I cannot recommend Sheffield & Meredith enough - great guys - know their stuff, prices reasonable and I'll definitely be using them in future.

Hope this info helps someone at some time in the future.
Rich