I NEED URGENT ADVICE: Electrickery/Alternator and a stupid owner??

Good afternoon!

My S3 is having a bit of a fit over it's electrics. The symptoms are the blinkers sometimes don't blink (either stay on or off) or they do blink but not consistently and not as quick as they used too. I also have a radio wired in which cuts out then turns back on. The ALT light is coming on when the engine drops to idle and sometimes staying on sometimes going off again so I'm guessing the symptoms are (at least) to do with the voltage being insufficient at times? Is this right or is it a problem with a bad earth perhaps or even the alternator itself (though I would have thought if so it would be a lot more problematic and not just when the revs drop).

The poor things MOT is up in two days so I need to make sure the basic electrics are working okay.

Sidenotes:
1) I changed the fan belt a few months back and tightened it as best I could but unsure if perhaps I need to get more tension in it in order that it drives the alternator sufficiently?
2) My exhaust manifold is blowing as I need to tighten the studs up to seal it (will do as soon as I get some imperial nuts) which makes the engine run rubbish which doesn't help
3) I have never had the car tuned as I believe it should be. I have to have it idle higher than I'd like to keep it ticking over without the alt light coming on. I say "idle higher" based on limited experience of how low other S3's I have heard idle at and what I have read.

Get your multimeter out and set it to volts. Check battery, it should have 12V+ there. Start engine, at idle it should creep up to between 13.5 to 14.5V. Or thereabouts. That means charging sys is charging how it should. With volt meter connected start engine, while cranking the volt meter should be around the 12v mark. During cranking if the battery plummets to say 9 to 11V or lower the battery is cactus.


Another simple alternator test is at engine idle turn everything on, lights, blinkers, radio, hair dryer everything and measure the battery voltage. If battery shows 12V+ the alternator is doing a good job. Under 12V not good.

Dont rule out bad connections eg, cleaN battery posts and clean up a couple of earths before doing the test is better.

Dr

1) Alternator belt tension...the belt should move, but be firm. There is probably a technical way to test it but everyone I know does it by feel! The above tests should confirm that though. As a side note, you want to leave the voltmeter on for long enough so that you test voltages when it plays up.

2) Sort it then

3) If you are having to increase idle to get it to run could be a whole host of things - something as simple as the timing out, worn plugs, incorrect plug gaps, worn points/rotar, incorrect fuel mix. Could be worn carb etc. First thing I would try is to take the plugs out and see both the condition and colour of the plugs - might give away some clues. "tuning" a series land rover is a very simple process - i would not take this to someone to do that.

Sounds like earthing problems to me. Apply WD40 or similar round the whole car from the battery -ve to the block .... starter .... then lights. Then check on your alternator... whether it's working or not won't affect your lights unless the battery is right down.

If your not sure on charging perhaps you'd find it worth getting a Start-Check by Gunson - useful as it gives you cranking power which a meter won't. I've had one for about 20 yrs now and well worth having.

Sound like the alternator is on its way out - they eventually wear out. If, after cleaning up all the connections you still have electrical problems try replacing it. You can get overhaul kits but they're reasonably cheap to replace as a unit.

The battery terminals are returning over 12v with full beam lights, indicator, heater on max and stereo on. HOWEVER, to get it to show over 12v I had to increase the idle speed screw until all electrics worked constantly and the ALT light went out on the instrument panel.

I've noticed as well that often in the dark the lights will dim as I slow down and brighten again as I accelerate (and increase rpm).

So before I go over all connections again (which I did fairly recently and couldn't see too much wrong) can I ask the question: Would a alternator that's on its way out, still work but only work well when receiving greater input/higher rpm and then cause the kind of symptoms I'm experiencing when the engine returns to (what I believe to be) a more normal idle/lower rpm? OR, would a duff alternator just cause me problems all the time?

It's being made harder by engine running awful because of manifold problem (to be fixed tomorrow - no imperial nuts today!).

I will go and check the plug colours, they have only been in 4 months and looked okay when I replaced them but will recheck.

Points/rotor arm etc. all replaced in Jan too and gaps etc. set appropriately. I haven't messed with the timing yet as it will be yet another first but I fear I may have to soon even if it's just to rule out problems there in the future.

Thanks for all the input so far. Any more opinions welcome whilst I go out and crack on with the next lot of jobs. AND if anyone's near Bracknell pop round and I'll make you a brew

DrWatson: Idling (with the idle now set much higher until ALT light goes out) shows a reading of 13.5v on the battery. Reading falls to around 11-12v for a second when initially cranking but engine warm so starting immediately and reading then jumps back up.

plugs look carbon fouled to me... I have been avoiding doing the timing because I don't know what I'm doing but think I need to start that now because so much other stuff seems to be dependant on timing already being done I never really know if I'm fighting an impossible battle.

I will check all the essential electrical contacts again tomorrow. Can anyone give me a simple direction on what - as a minimum - I need to check. e.g. batter to solenoid to coil to starter to blah blah etc?

Thanks.

The alternator output is controlled by the current in the rotor field coils which in turn is controlled by the regulator circuit in the alternator. The field coils are fed by a commutator and brush arrangement which will suffer from wear and prevent the regulator doing its job properly. Replacing the brushes may well fix your problem but you need a fairly good soldering iron to remove the diode block to get at them. Replacing the entire alternator is simpler and not too expensive.

I agree with Oxides, I think there are only 3 bolts to replace the alternator, done in about 15 minutes, and if you can't get hold of one then I have one in the garage somewhere, but there's plenty on ebay.

Better car accessory shops often have an alty test jig, for a tenner they'll tell you whats up with it if anything, strongly reccomended.
The fact that you say you have 13.5v suggests that the alty is working.
A short to earth somewhere on the wire that goes to the alty from the warning lamp would cause something like this, had it happen the odd time.

Water247 said:

DrWatson: Idling (with the idle now set much higher until ALT light goes out) shows a reading of 13.5v on the battery. Reading falls to around 11-12v for a second when initially cranking but engine warm so starting immediately and reading then jumps back up.

Click to expand...

If the vehicle is at idling spec and lights and radio etc are on, and you are getting under 12V I would suspect the alternator. The battery should be right but its hard to assess when the idle is beefed up higher. With an underperforming alternator the light will come on.

Can I suggest getting the engine sound, ie, manifold leaks fixed, timing, carb setup, and all that fixed. I concur with dr peppers comments on checking the alt wires for cleanliness at connectors and wire insulation. Dr.

have you tried another battery beg borrow etc sound like the alternator is charging try checking terminal and crimp lug's on main leads and battery lead to and from starter solenoid .

I have now put in a new battery so eliminated that, also replaced the alternator to no avail.

I fixed the exhaust manifold to exhaust downpipe hole (hopefully for the last time!) and the engine will at least now idle.

I have WD40'd most obvious electrical bits and given easily accessed connections a quick wipe and tighten.

I still have two remaining problems....

The first is this electrical one of blinkers not blinking at correct or any frequency, radio dying and ALT light sometimes coming on. This problem goes when the engine runs healthily or at higher revs and only comes back when the engine is idling or returning to low revs.

The second one is fairly new and I was going to raise a separate thread for it, but I'll explain it here and leave to you knowledgable folk to decipher what it is and whether it is perhaps causing any of my other symptoms.... SO, driving down the motorway a few days ago I heard a dull thud and experienced a temp drop in power which took me from my 70mph to 55mph. I drove for another mile to see if anything noticeable occured but no more noises and no vibrations or visible signs, however, power loss was now very noticeable so I pulled over. Couldn't figure what it was so completed my journey but with my new top speed of about 55mph instead of the 70 I normally get. Now, in the last few days since this happened the engine is now misfiring (I think they are misfires - It pops and bangs 2, 3 sometimes 5 in succession then nothing for perhaps another mile) and really struggling to provide power. When I press the throttle (clutch down or in neutral) the engine struggles to get going initially then kind of clears itself at the mid to high range rpm and seems better. Then releasing the throttle gives a lot of after fires now (pop, pop, pop as the engine returns to idle). The same thing happens when I put it in gear but with the additional strain on the engine it really struggles to get through those early range rpms to where it clears around the mid-high range. Today it was struggling to even clear itself at all - especially in 3rd gear and 4th gear was virtually useless. Whilst I've been tinkering with it on the drive all afternoon I noticed at idle it goes through periods where it is struggling to just idle (and the electric problems occur during these times), then suddenly it will begin idling much more nicely and the electrical problems go away. It may idle nicely for a minute or 15 minutes then returns to struggling for a period and repeats the cycle. I have also noticed that I get white smoke/vapour come from the carb after the engine has stopped, the last time the engine stalled the white smoke actually poured out of the air holes in the top of the air filter. I get similar smoke from the exhaust each and every time I start the car up - but not whilst it's running.

I have cancelled my MOT appointment tomorrow as can't rely on blinkers passing if it's idling rough so tomorrow I intend to learn how to check the timing and to start an end to end clean-up of all the electrical parts.

In the meantime, if this new information sheds any more light on my poor babies ailment then I'd love to hear any thoughts.

Thank you very very much as always for everyones helpful AND QUICK responses so far.

Andy.

Sorry to hear about your problems, but you were doing very well to be getting 70mph, I'm afraid I don't know about petrol landies, but I'd suggest that if you're not in too much of a hurry or strapped for cash then order all the parts you will need to give everything a service, including head gasket, stem seals, distributor cap, HT Leads, plugs and fluids etc. You can easily do the whole lot in a few days even without much experience, they are incredibly simple to work on and you will quickly get to know the beastie inside out, and sort the timing while you're at it, just make sure you wait for the parts to arrive before you start! but this definitely seems the place to come for help if you need it, even if I can't help!

This morning I was about to sort the timing and just fiddled with the screwy advance bit on the dizzy and realised it was screwed to advance a fair bit. I havevn't ever touched that but I did overhaul the dizzy in January so perhaps it was a result of that. I took this right back until the screw wouldn't go any further and the engine ran immediately better - so much so that it seemed reliable enough to keep my blinker vodoo at bay most of the time so I thought I'd quickly take it for MOT and chance my arm.

It failed but with:
OSF headlamp insecure (it wasn't until he started pushing it!)
OS and NS ball joints having excessive play (I suspected they would but ran out of time and didn't get to check them myself)
NSF brake pipe inadequately clipped, and,
OSF tyre clips the leaf spring when steering on full lock (thanks to previous owner putting offroad tyres on without adjusting the steering lock

So nothing major and nothing that was that much of a shock.
Chassis was barely checked but looks pretty sound to a casual inspection.
I noticed whilst it was on the ramp (though the tester didn't) that the OSF suspension mount was cracked one side which I guess will need to be welded to fix.

In typical Landy stylee I got the following advisories:
Engine has major oil leak
Gear box has major oil leak
Both diffs have major oil leak
NSR back plate has oil contamination



So hopefully not too hard to do the work and get it through a retest in the next 10 days. However, a lot more to do afterwards and I still have the problem of it running like a dog since this thud but as that doesn't look likely to affect my MOT I may just have to live with it until the essentials are complete and I at least have another 12 months MOT under my belt.

Andy youve got a host of described problems there. You really need to get a workshop manual and do the timing , ign and carb to spec. What your describing is engine timing and electrical probs, ie points and leads etc.

The electrical prob sounds like a possible short going on thats putting a sudden drain on the voltage and upsetting the flasher in the blinkers , radio etc. I wonder if the blinker switch is shorting internally? Does it feel worn and a bit sloppy?

Just a suggestion, check wiring start at the battery and give it a good looking over and see if there is any visible insulation cracks. Re-route wire as appropriate if its near or touching metal.

Id have a close look at the wires and connector on the alt as well, trace it back .

Intermittent faults are hard to nail. Dr.

Hmm, this sounds familiar - thump from engine, loss of power, ignition timing suddenly out. Mine did this once and I had to rotate the dizzy round quite a way to get it back in. I can only assume the dizzy/oil pump cog slipped a tooth 'cos I can't think of anything else that would do this.