Alternator or battery fault?

[brorabongo]

This afternoon I noticed the the bongo turned over for longer than usual before starting. Then drove around 180 miles ok, but then the leccy started to fail. First I noticed the wiper was slow, then the mason alarm was giving a low reading, then the "4W ABS" light stayed on. When I went to switch on the blower, the radio went dead along with the speedo, and rev counter. After a short while the radio started up again. but the futher I drove it was getting worse. Just a couple of miles from home the headlight dimmed the indicators would not work, and "4W ABS" light was very dim.

Once home, I left the engine running, and tested the battery for a voltage. I was only getting 4.5V, but when the engine was revved it would rise to 5V. Should I not be getting 12+ Volts?

I have the battery on charge as we speak, but it's too dark now to be trying to test the alt.

So would you say it's most likely to be the alternator that is to blame?

The alt is only a year and a half old, and the battery must be 4+ years old. ( all the writing is in Japanese)


Cheers.

[mikexgough]

I'm not a leccy techie to the degree of internal workings of gizmo's but the last time I had your symptoms my alternator had "gone" and as a consequence it "cooked" the battery so I had to replace both..
My current battery is a Jap one.... so as we are approaching the colder starts and not knowing the age....I am getting a new one tomorrow..... one recommended in the factsheets for the princely sum of £47... from a local motor factor at trade price...

[munroman]

Hi Donald, glad you just got back OK!

One thing which might be worth checking is the earth leads from the engine, and from the battery to the bodywork, I have had similar weird symptoms on a couple of vehicles and it has been the earth strap corroded/broken, in one case the engine was earthing through the choke cable which was 'interesting'.

If you have jump leads, a quick check would be to clamp one onto a head bolt or similar, to a body earth, and similar for the battery to earth and see if that helps.

Good luck and I am glad you got home, albeit a bit fraught I am sure!

Slainte

Derek

[brorabongo]

Cheers guys I'll look in the morning. One thing I forgot to add was at no time did the charge light come on, plus at times the airbag warning light would pulse....that was worrying!!!!

Was great to meet you Derek, although it was only for a short time. I sure we'll catch up again sometime.
I'll put my pictures up in the section later.

[madmile]

Have you put in a leisure battery and changed the wirng for the radio etc over to the leisure battery. If you have, then this sounds symptomatic of the LB failing, or failing to charge.

[brorabongo]

No leisure battery, I got hold of a tray for one though ( Thanks OGGY ) and use it as a tool box tray.

[mister munkey]

From a numptys point of view, if the alternator is feeling even slightly unwell, it tends to flick up the charge/sediment lights.

From the sounds of it these are the only two you've not been bothered by!

I'd suggest the alt. is fine & you need to be looking elsewhere for the gremlins.

[dave_aber]

engine running, and tested the battery for a voltage. I was only getting 4.5V, but when the engine was revved it would rise to 5V

Alternator should be kicking out 13-14v, should be reasonably steady, but will increase a wee bit when revved.

If your alternator wasn't connected to the battery any more (e.g. a broken wire) you wouldn't see the 4.5v going up to 5v.

So, either your alt is generating a much lower voltage than it should, or something big is causing a massive voltage loss. A really screwed up battery might cause this.

As soon as the voltage level coming from the alternator is lower than the voltage in the battery, your charge light should come on.

If there was something in the line dropping 12v down to 5v, then I'd expect fuses to be blowing etc.

I'd be for recharging the battery overnight, as you are doing, and get in about it in the daylight. With the battery on the bench and recharged, it may well read 12v on a meter - you really need a battery load tester to be sure (Mahoosive resistor with 2 big probes, and a meter).

If you do get the engine re-started, measure the voltage across the battery with it running - expecting 13-14v. If this is 12v, and doesn't change with revs then your alternator/rectifier is shot. If you are back to the 4.5-5v symptoms, try disconnecting the neg lead off the battery, and measure volts between the + terminal and the chassis/ground. If this is 13-14v, then the battery was dragging the level down (and I doubt the engine would have started).

Do you have access to a portable starter pack? Lift the terminals off the battery, and connect the leads of a starter pack directly to the car's battery cables with the main battery out of circuit. Then start her up, and measure the voltage across the starter pack battery - 13-14v expected again.

A duff battery may have blown the rectifier in the alternator, so you may be looking for 2 faults now.....

Best of luck!

[g8dhe]

People have covered most aspects, but one thing to check is where your measuring the battery voltage - I suspect the battery terminals, that's fine - BUT also check between chassis and ideally the Blue 100 Amp fuse (side away from the battery) in order to check out the alternator itself, if its the same as across the battery terminals themselves then its less likely to be a wiring/corrosion problem.

[mister munkey]

2 & a half hours from posting problem to several portions of World Class helpful advice!


What a crew - I Love This Place!!

[catzi]

Flipping heck it must be catching.

My wife went to start the Bongo this evening and the battery was flat. This is the second time that the battery has gone flat in the past month or so. Jump started it no problem (it was in the local railway station car park) but its too wet and dark outside to get the battery out tonight and put it on the charger.

Last time it happened I put it on charge overnight and it seemed-right-as-rain but I assume the battery level is dropping over time. The charger I've got is one of these all-singing, all-dancing jobs that is supposed to diagnose battery faults but it didn't find any.

Given my limited knowledge of batteries/alternators, am I looking at checking pretty much the same stuff as has been recommended for BroraBongo?

Thanks,

Iain

[munroman]

Flipping heck it must be catching.

My wife went to start the Bongo this evening and the battery was flat. This is the second time that the battery has gone flat in the past month or so. Jump started it no problem (it was in the local railway station car park) but its too wet and dark outside to get the battery out tonight and put it on the charger.

Last time it happened I put it on charge overnight and it seemed-right-as-rain but I assume the battery level is dropping over time. The charger I've got is one of these all-singing, all-dancing jobs that is supposed to diagnose battery faults but it didn't find any.

Given my limited knowledge of batteries/alternators, am I looking at checking pretty much the same stuff as has been recommended for BroraBongo?

Thanks,

Iain

Is the Bongo doing only short journeys? It takes a lot of juice to fire it up, if it isn't getting a good run now and again that wont help. The short run to the railway station takes huge amps out of the battery, especially with lights/fans/Heated Rear Window drawing current.
Are any interior lights staying on, I think the rear interior light can pull current if it is faulty.
Any alarm drawing current?
Lights left on, buzzer disconnected? , I've done that! (Twice!)

I hope you get it sorted, I am now paranoid about mine getting it as it was close to Donald's on Sunday!

[steviebongo]

hi catzi it could be a dead cell in the battery I would get it checked as soon as u can just in case u get stuck sumwhere.



cheers stevie

[brorabongo]

What a crew - I Love This Place!!

I second that.

The red charged light is now shinning dimly on the charger. So hope to give the battery a test tomorrow along with all the other things to look out for. Cheers folks.

[catzi]

Is the Bongo doing only short journeys? It takes a lot of juice to fire it up, if it isn't getting a good run now and again that wont help. The short run to the railway station takes huge amps out of the battery, especially with lights/fans/Heated Rear Window drawing current.
Are any interior lights staying on, I think the rear interior light can pull current if it is faulty.
Any alarm drawing current?
Lights left on, buzzer disconnected? , I've done that! (Twice!)

I hope you get it sorted, I am now paranoid about mine getting it as it was close to Donald's on Sunday!

Yes, that probably explains it. Most if the time the Bongo's used as a second car and mostly, my wife uses it for going back and fore to the railway station. Probably a ten minute journey at most.

Will have to think about ways we can run it a bit more if we aren't planning any trips away. Maybe plan more trips away!

One question however, I'm not sure of the age of the battery, would matters improve with a new one?