tuko Posted January 7, 2006 Share Posted January 7, 2006 Just like the post says, How do you know that your alternator is on it's last leg? Today we we out all day, playing in the snow. After a nice warm meal at a friends and watching an off road DVD, we piled into the landy and drove 60Km home. When we got back into town, we stopped at the local grocery store, to get some chips and such for the evening munchies....everything going well to this point. Of course at the grocery store, I turned of the engine....Tried to start it 15 minutes later....Dead battery! I did notice that the high beams we some what dim driving home and the dash lights we darker than normal, but hey, it's a series 3, it does funny things sometimes. So a half hour later I had the wifes car and my set of jumpers. Used the car to start the landy and drove it home, with the wife following closely behind, if something did happen. Once home and the motor still running, I put the amp meter on the battery and it showed that the alternator was charging! Ran the motor for a bit, tried to start it several times, without any problems.... I'm wondering, is this the early signs of the alternator is on it's final legs? I've never ran into this problem before, on the landy, so, what do you think? Todd. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 8, 2006 Share Posted January 8, 2006 Is it petrol or diesel? The alternator on dad's RR has "died" several times now (no battery light lit, just no charge ) each time the brushes were stuck due to mud . Remove brush pack, clean, wiggle the brushes to make sure they spring out to make contact OK and replace. Quote Link to comment Share on other sites More sharing options...
tuko Posted January 8, 2006 Author Share Posted January 8, 2006 FF, "(no battery light lit, just no charge )" Good Point, and that's exactly happened to me, no warning at all. Todd. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 8, 2006 Share Posted January 8, 2006 My theory, wot is mine that I wrote and has my name on it, is that the brushes stick and provide just enough contact to prevent the charge light coming on but not enough pressure to generate any leccy. "We" are now going to install a voltmeter in the RR to keep an eye on things Quote Link to comment Share on other sites More sharing options...
pritch1 Posted January 8, 2006 Share Posted January 8, 2006 Have u checked the earth from the engine. i had a strange problem where my old 2.5na desil would kick over some times and not at all others and it was the fact that the earthing strap had a bad connection and decided it would work sometimes and not others just an idea Quote Link to comment Share on other sites More sharing options...
GBMUD Posted January 9, 2006 Share Posted January 9, 2006 Tuko Try connecting a volt meter to the battery with the engine running. You should get about 14v - a little less with a flat battery (as it is charging hard) or a little more with a charged one. Now, start turning things on, lights, heater, wipers, de-mister if fitted. Keep an eye on the volt meter all the while and see if it drops to below about 12.5v. I rekon it will. Have you "uprated" anything in the electrics? Extra or brighter ights, extra electrical devices, heated windscreen etc? I expect that a S3 will have been fitted with a 45A alternator from new so it is quite easy to overwhelm this with extra goodies. Check also that the alternator drive belt is tight - the one on my Defender seems to need regular tightening, the main symptom being reduced output voltage especially under load. It is possible that the brushes are stuck but, in my (extensive) experience they get muddy, stick and stop working within a few minutes and then stay stuck until you free them off. Well worth checking that there is plenty of brush there though and that they are springing onto the slip rings properly. Chris Quote Link to comment Share on other sites More sharing options...
Daan Posted January 9, 2006 Share Posted January 9, 2006 I have had mine doing this. It turned out it was the connectors to the alternator had corroded. Quote Link to comment Share on other sites More sharing options...
tuko Posted January 11, 2006 Author Share Posted January 11, 2006 Replaced the brushes and the battery ground cable.....still have a flat battery! Tomorrow I'll check the system to see if there is a short somewhere's. Note: When I was driving home from work, the headlights and heat were on, when I turned off the lights in the driveway, the heater came to life. There is 2 relays in the headlights circuit, could a relay be gone? OR is the heater drawing too many amps ? (no relays there) Todd. Quote Link to comment Share on other sites More sharing options...
simonr Posted January 11, 2006 Share Posted January 11, 2006 Have you had your battery drop-tested? Very often the alternator wires go to the starter motor and from there to the battery. Check that the stud to which they both connect is done up properly. The charge light only indicates that the alternator is generating charge - not that it's getting to the battery. As Chris says, stick a volt meter on the battery - perhaps leave it on there for a few days - and see what circumstances cause the voltage to dip (apart from starting). Try the same with the VM connected to the alternator. If the circumstances differ, then there is a bad connection between the two. Si Quote Link to comment Share on other sites More sharing options...
tuko Posted January 12, 2006 Author Share Posted January 12, 2006 "Check that the stud to which they both connect is done up properly." Would you believe it, the connection form the alternator to the start solenoid was loose. Lets hope that's all it was. Other that that, everything looked to be OK. I'll keep an eye things for a few more days. Todd. Quote Link to comment Share on other sites More sharing options...
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