Thread: Battery warning light

Hi Mark,

I have a '99 Disco II V8 and it occasionally starts up with the red charge light on. I find that if I just turn the engine off and restart, the light always goes away.

I suspect my alternator is a bit dodgy, but since I bought it off eBay for USD$100, it's not too shabby.

I do carry a spare alternator in the back of the vehicle, but have yet to use it, and I've crossed the Simpson last year no problemo with this very intermittent problem.

G'day,

I'd start by checking all your connections first. That is both battery terminals and earth point to the chassis, followed by the connections on the back of the alternator. (They have a habit of working loose).

Then get a multimeter (Set to measure voltage, red lead to +ve (positive) side, black lead to the -ve (negative) side, and measure your battery voltage (without engine running). Then start the car and measure the voltage again. Voltage should increase from around 12V with the engine not running, to about 13-14V with it running.

Hope this helps

it could also be the brushes in the alternator getting stuck......may be dirty.....
they may even be worn......



if your alternator has a small black module externally like the late model cars such as commodores......
it may be just a simple matter of replacing this module.....this is the actuall brushes.....

this part is around the $35 dollar mark.........

Check first things first - is your fan belt loose?
John

Thanks for the tips guys, I'll do some fiddling tomorrow lunchtime. I searched the site earlier and found heaps of stuff for batteries and alternators etc. but nothing about basic checks; a bit like searching a cooking site for how to make toast! But hey, you have to start somewhere...
I fitted a new belt last week along with the tensioner bearing and on that point I can proudly say that, at the tender age of 38, I now know what to be when I grow up: Landy grease-monkey! Well, if MLR want $500-odd for fitting a new tensioner and all it took was an hour and a $6 bearing from work; that's a good feeling!

Originally Posted by markyc

Thanks for the tips guys, I'll do some fiddling tomorrow lunchtime. I searched the site earlier and found heaps of stuff for batteries and alternators etc. but nothing about basic checks; a bit like searching a cooking site for how to make toast! But hey, you have to start somewhere...
I fitted a new belt last week along with the tensioner bearing and on that point I can proudly say that, at the tender age of 38, I now know what to be when I grow up: Landy grease-monkey! Well, if MLR want $500-odd for fitting a new tensioner and all it took was an hour and a $6 bearing from work; that's a good feeling!

The battery warning light problem didn't start after you fitted the belt and tensioner did it >

No, a few weeks before. At first I put it down to moisture as my beast lives outside. The warning light seemed to coincide with damp mornings but lately it's happening nearly every other turn of the key. I'm just worried that one time (next time?) I'll find my battery dead.

here is a picture of what i was talking about earlier.....




you can see the brushes on this one quite easily....if these are worn they will not be making contact.....
if they are gummed up with dirt they may be getting stuck istead of springing out onto the slip rings.....

if your alternator has one of these it will be on the back of it.....the wiring plugs into it......
it may look slightly different.......

two screws and they come off.....just make sure to disconnect the battery first......