Generator problem in a TDi 110

[manoova]

The battery light won't switch off on in my 110. Taking a look under the bonnet it seems the generator is producing power, but it's not delivering it to anything (neither the battery nor the engine...if I disconnect the battery with the engine running the engine dies - though on a couple of occasions while trying to work out what was wrong it did continue to run). The battery light sometimes dims after a minute or so at high revs, but doesn't go out altogether. I can't see any obvious loose wires anywhere. I was wondering if anyone here might recognise these symptoms and offer a diagnosis. Thanks.

[Adz]

Check both the condition and tightness of the v belt which drives the alternator first - if it's slipping due to serious oil contamination, for example, it won't drive the alternator fast enough and the charge light will glow.

Next check the alternator connections - there should be two of them - one big fat fella and a little skinny one. It's the skinny one we're interested in. Check the spade connector isn't loose/dirty/broken - this is the energiser/exciter wire for the alternator, if there's anything wrong with this the alternator won't provide any charge.

Let me know if all the above is ok or not and I'll see what else I can come up with.

Cheers,

[manoova]

Thanks Adz,

The belt is tight and the alternator whizzes around; and the connections look okay (I have three - a fat one and two skinny ones).

I've been wondering whether the alternator is just kind of dying slowly in fits and starts.

Sometimes the battery light goes dim when the revs are increase and sometimes it doesn't.

Sometimes the engine quits when I disconnect the battery, sometimes it doesn't (it quits more often than not).

I get a charge from the upper of the two skinny wires when the alternator is rotating (there's always a charge in the fat one as long as the battery is connected).

Unfortunately my workshop manual has next to nothing in it about the alternator.

Any more ideas/suggestions would be very much appreciated.

Thanks again.

[Adz]

Trying a known working good battery first before changing the alternator, or getting the existing battery tested is probably the cheaper way to go about it - otherwise a new alternator is looking likely.

If you're in the UK then http://www.paddockspares.com is probably going to be your cheapest source

200 Tdi: http://www.paddockspares.com/pp/DEFE..._-_200TDI.html
300 Tdi: http://www.paddockspares.com/pp/DEFE..._-_300TDI.html
or: http://www.paddockspares.com/pp/DEFE..._-_300TDI.html

Cheers,

[manoova]

Thanks again Adz. Sorry for not showing my appreciation sooner. Been up to my elbows the past couple of weeks fixing the same problem in my plane...which was kind of a strange coincidence. Turned out it was the voltage regulator in the plane.

Reckon the Land Rover needs a new alternator though.