Alternator or battery fault?

[munroman]

Hi, If I had a pound for all the cars with problems due to short journeys!

To be honest, a new battery might help a little, but here is a way to picture what is happening.

Imagine that the battery is a tank full of water. Every time you start it, some water runs out. Every time the engine runs, some water gets put back in.
If you only do short journeys, more water runs out than goes back in, so the tank empties, (battery goes flat.)

An old battery can be like a water tank with a small leak, so it will go flat sooner, but the main issue is probably the pattern of use it is getting.

Is there any way you can put it on a mains charger even once a week or so, as it is bad to have a run down battery in any case as it harms the battery?

Or, convince your wife that by the time she de-ices the Bongo and parks up, she would be as quick walking to the station!

[brorabongo]

Bad news.........My old battery will not keep a charge.

Good news........Oggy has kindly lent me his from his scrap bongo.

Bad news.........My alternator ( under 2 year old) is only outputting 11.98V Measured at the alt.

Bad news.........Oggy had already sold his old alt.

[dave_aber]

Well, at yeast you are on to something.

Is your alt actually generating anything though - is the 11.98v coming back from the battery? Does that figure change with revs? Could be a duff rectifier or brushes on the alt. Not sure if the rectifier can be changed on these alts, but the brushes should be.

Presumably, the dash charge light should have come on with this fault - is the bulb OK?

[catzi]

...Or, convince your wife that by the time she de-ices the Bongo and parks up, she would be as quick walking to the station!

Ha! ha! ha! If you'd like to tell her that 'cos I'm not!!

Battery's on the charger now though. I think the battery is pretty old so will think about replacing it if I can find one at a reasonable price.

Cheers!

[munroman]

...Or, convince your wife that by the time she de-ices the Bongo and parks up, she would be as quick walking to the station!

Ha! ha! ha! If you'd like to tell her that 'cos I'm not!!

Battery's on the charger now though. I think the battery is pretty old so will think about replacing it if I can find one at a reasonable price.

Cheers!

I can assure you that I come from a long line of devout cowards, so there is no way I would even mention it!

(Seriously, one of the best things you can do for any vehicle, especially in winter, is to give it a decent run where everything heats up, dries out and all the crud which builds up in short distance running gets cleaned out)

Good Luck!

[buddyh42]

the short run theory cannot be Broras problem, maybe his actually needs some small ones....LOL EH!!!! Donald... what did you think of my local shopping centre then ?

[bongoben]

Presumably, the dash charge light should have come on with this fault - is the bulb OK?

Alternators need an excitation voltage before they start to provide output
current, this should be provided via the Field (F) terminal on the alternator.
Most manufacturers now use the ignition light to excite the field coils and
if this doesn't light up when you switch the ignition on; then you probably
won't get any output.

As the alternator is a 3 phase generator; you can lose up to 2 pairs of the
six diodes and still get an output from 1 phase sufficient to raise the output
voltage to above 14 Volts. With a healthy alternator you should be measuring
around 13.8 Volts with the engine running at tickover speed - 800 rpm - and
around 14.4 Volts with the engine running at 1500 rpm.

If the engine is running and you are measuring 11.98 Volts at the alternator
output terminal; then there is no alternator output and you are measuring
the battery voltage - and a fairly flat one at that.

[brorabongo]

Striped alt down, and the brushes are ok. I had an old alt that had bearing problems, so looked at trying to get good alt out of two, but as you can guess they were totally different.

S/H Alt ordered, Via Bellhill. Posted tomorrow DHL 48hour delivery, which I can guarantee means I'll get it on Monday.

[Kitegirl]

I too am having problems that we can't work out whether they've caused by an incapable relay system, or a shot alternator..

Am having intermittent times when the battery won't start, even after driving 200 miles and only stopping at services for the loo..

Also, the leisure battery isn't lasting long, and blows the 30amp fuse all the time.

Most recently when we're driving and have lights, stereo and maybe phone charger on, the stereo is switching off and the internal lights are low..

It's mighty worrying

[mikeonb4c]

I too am having problems that we can't work out whether they've caused by an incapable relay system, or a shot alternator..

Am having intermittent times when the battery won't start, even after driving 200 miles and only stopping at services for the loo..

Also, the leisure battery isn't lasting long, and blows the 30amp fuse all the time.

Most recently when we're driving and have lights, stereo and maybe phone charger on, the stereo is switching off and the internal lights are low..

It's mighty worrying

Sounds very odd to me, like its leaking away massively somewhere (intermittently?). Unless handy with a multimeter etc. youselves I'd get an auto electrician onto it pronto. It oughn't to be that difficult for a pro. to track down

[MountainGoat]

I had similar battery prroblems when I first got my Bongo from the converter. Turned out that the split charging system that they installed was rubbish. Replacing it with a Willinton Intelligent Split Charging Wiring Loom solved the problem for me.

Tony

[brorabongo]

Second hand Alternator in and we're up and running. Now when at idle I'm getting a 14.32V reading at the battery......thats more like it.

Now I off looking for the biggest battery I can fit.

[mister munkey]

I just luv a happy ending.

[missfixit70]

That sounds much healthier

[MountainGoat]

Now I off looking for the biggest battery I can fit.

This should do the trick Donald, this is the one that I have got in my Bongo.

Use the Motaparts.Com website rather than the electronic catalogue to find Motaquip Battery part no.VBZ44 (12v 105A). Using the Quick order facility it shows that the current cost of this battery is £57.06 + vat with a standard delivery of £13.98 unless you can source one locally.


Tony