Battery power drained in 15 mins - V8

[beattiedh]

Hi All

A little guidance please. 3.5V8 EFi

Popped out today and when parked I noticed the engine revs dropped and the rev counter stopped.

When I turned the engine off the battery light came up.

when I restarted the engine the alternator was making a small noise and smelling slightly. Managed to get home but the battery light is still on and the rev counter not working. The alternator was then smelling a bit more and was quite hot.

The battery is now totally dead.

Is there a short that is draining the power or has the alternator gone and would it cause such a power drain?

She has been for a little swim recently, would that have caused this?


Any help would be great.

yours

Duncan

[Budgie]

It does sound like the alternator is U/S but exactly what has gone wrong I'm not sure. If you were running lights, radio and starter etc then it may have drained the battery that quick, how old is the battery? If you've had it for a few years then it may not be in best condition itself.

If the photo is the deepest you went wading then I wouldn't think that water got near the alternator on that trip, there again, did you go through deeper or at a faster speed? That may have put water through it but again, it shouldn't have cause a failure.

If you've got an auto-electric shop near you then I would take the alternator in for testing and see what they say.

[muddyweb]

I'd go for the alternator too... the fact that the tacho stopped is probably related too.

In any case, get your battery on charge ASAP... if you leave it discharged it will be ruined in a short time.

[Disco Inferno]

i'd also go for alternator -  the same happened to mine a few months ago

battery light on when engine off and and getting really really hot

[beattiedh]

Hi Guys

Many thanks for the advice

Will go and check the alternator.

Thanks

Duncan

[datalas]

I'd plum for the alternator, the Rev Counter was the first thing to pack up on the disco when Bramcote utterly destroyed my last one...

Consider finding a local sparky, mine was reconditioned (same day service too) for £30, came back lovely and shiny.  Shame about the rest of the engine bay :)

[Range Rover Blues]

Are you sure the alternator is still spinning, the burning smell could be the vee belt loosing it's battle.  The rev counter is a dead giveawy.

Check your local scrappy, I picked up a good spare for £15.

[hobbit]

Find out the model number of the alternator, they will service more than just discos, then you can see what other vehicles run them, handy when looking round for a 2nd hand one

[beattiedh]

Hi

Started the Jeep and charged the battery on the Disco. Once some charge was in she started was still running but the alternator was starting to smell and was getting hot.

All relevant cables and belts attached and running as normal.

However still no revs showing on the rev counter and when it was turned off the vbttery light was once again on. It then drained totally within about 4 mins.

What would cuse the battery to drain so quickly when it is turned off?
Where is the signal for the rev counter coming from?
Would all of these come from a shagged alternator?

thanks

Duncan

[muddysteve]

However still no revs showing on the rev counter and when it was turned off the vbttery light was once again on. It then drained totally within about 4 mins.

What would cuse the battery to drain so quickly when it is turned off?
Where is the signal for the rev counter coming from?
Would all of these come from a shagged alternator?

thanks

Duncan

Yes - ALTERNATOR!!!

get a new one, they're not that expensive or if you can afford to have the car off the road for a while take your shagged alternator off and get it to an alternator place. (there's on in northcamp near me if you get stuck)


Steve

[Budgie]

It does sound like the alt' is well gone.  :(

The rev counter takes it's readings (pulses) from the black & white wire that goes into the back of the alternator. If this isn't sending anything to the rev counter than it may not be sending any charge to the battery either.

Did you have time to check if there was any feed to the battery from the alternator?

The battery may have drained so quickly because of a short in the alternator using the power. If the alternator wasn't charging the battery then the only power stored in it would be from the small charge it got from the Jeep.

As Muddyweb said earlier, I'd get a charger on the batttery ASAP if it's now been totally drained twice. This will damage the battery if it not recharged soon.

[Budgie]

The rev counter takes it's readings (pulses) from the black & white wire that goes into the back of the alternator.

DOH! I've just noticed that yours is a V8 so it may have different rev counter supply to my TDi.  :?  
I'm sure someone will know.  :D

[Range Rover Blues]

If the red light stays on when you turn off the engine then it's the rectifier pack in the alternator that's gone, this is what's draining the power too.  It's worth having your unit rebuilt IF the bearings are ok, check when you take it off.  The parts are about £20 plus fitting, our local specialist did it for £30 cash, I only paid because mine is the 80-amp unit which is different from the 60-amp unit, you can pick up a spare for £15 (did I say that already? :? ).

[datalas]

Depends on your local sparky really, as I say, mine was jolly cheap and included replacement bearings, principly because bramcote had turned the contents of the poor thing into dust :(

[beattiedh]

Hi Guys

Took the unit to the Burfield Starter and Alternator Centre. Nice little local company. They tested it and it was truly cooked. Got a recon with a full years warranty for £45 inc VAT. Emaculate condition.

Will be fitting it later in the week when I have some time.

Thanks for your help.

Dunc