Alternator problem

Sounds like the diodes to me, same symptom as my car. I bought a new alternator from the auto electrician with greater power and machined the pulley a little to suit. It s possible that two old alternators could have the same symptom. All alternators have diodes in them as far as I know, since the output is DC. Old cars had generators the AC was rectified at the commutator and brushes so they had no diodes. The external regulator if fitted is isolated from the power when the key is off, it could be a faulty ignition switch. If you have the wiring diagram, I have only he defender on but similar i guess. Turn off the ignition
disconnect the positive cable and connect a test light, ( a parking light bulb is a good one) into the circuit, one side to the battery the other side to the positive cable, if you have leakage the lamp will come on, the brighter the light the bigger the leakage.
Identify the fused connections to the positive, ignition switch, demisters, lights etc , remove the fuses one at a time and check if the light goes out, if it goes out you know which circuit the leakage is in. check the starter motor cable for grounding or leakage. disconnect the alternator ( at the alternator side ) if the light goes out it's the alternator. good luck :cool:

if you want and can make it swing on out I'll be doing a heavy spannering day on saturday with a bloke who needs help to do a heap of maintenance work on a td5 90.

happy to play auto sparky for you if you can get here.

I think I'll just buy the alternator in the eBay listing.

If you don't want to risk wasting money on another alternator, I highly recommend simmo's advice to double check where you are losing power first.

I know there's power flowing through the alternator due to the following:
* fitted replacement alternator late Saturday;
* started ok Sunday, took it for a drive;
* Monday battery low, wouldn't start, ran started down drive way;
* parked at train station for the day, restarted at station to check if charged enough;
* 6pm battery flat, called RACQ, clamp meter showed current in leads from alternator while ignition is off;
* put battery on charger over night;
* Tuesday & Wed I've been unplugging alternator (rear of alternator) after driving, reconnecting when driving, and battery has been ok.

However, you're right I'll also check using a test light before I buy.

Those ebay ones are a low quality aftermarket job. The part numbers are only for cross reference.
If you've got a genuine denso or mitsubishi etc I'd recommend getting that repaired over buying the ebay one.

If you really want a new one, buy one from one of the local ebay vendors with a 2 year warranty...

Steve

It's a Hitachi 12v unit which sounds like being unique in Australia to the Perentie. Other 4BD applications are generally 24v. I was quoted prices $1200 through to $2000 from Isuzu for a replacement Hitachi. . I don't have part numbers for other makes. The local auto electrician couldn't find a replacement.

Quote:

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Originally Posted by rar110

I think I'll just buy the alternator in the eBay listing.

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Hi mate,
I am just experiencing no charge from the alternator :(
I spoke with a friend of mine at the petrol station that has a workshop as well.
He told me that if it was the brushes, if you hit the alternator with the hammer with the engine on, the light on the dashboard should blink (mine didn't). If not it's time to replace.
Then I called a friend of mine how is an auto electrician in Italy and he told me that the alternator usually last 160.000/180.000km (mine is 165.000).
He said as well that the regulator is the first thing to go.

But my good news for you is this :D
I don't know the year of your landy, so....
....go here 90-110 & Defender Engine Electrics - Major Components at www.rimmerbros.co.uk and get the part number for your truck,

then go here Alternator - Land Rover Part ERR6999 and insert the part code, then choose the manifacturer you prefer (this example is for Td5).
Following the best-to-worst quality manifacturer:
Bearmach-Allmakes-Britparts
The first two are good, the third is **** :censored:
Trust me, including the shipping you will end up to pay almost 50% compared from anywhere in Oz. For my case is 500$ all together.

Cheers

Quote:

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Originally Posted by rar110

I know there's power flowing through the alternator due to the following:

............................current in leads from alternator while ignition is off; .....................................

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Your alternator's stuffed. There's (usually) six diodes in the alternator and it only takes one of them to be crook for this to happen. It's a very common fault.

IMO you'd be better off with an overhauled quality alternator than with a cheap POS Chinese knock off. It's not a difficult job, I'd expect somewhere around the $200 mark unless there's something particularly quirky about the Hitachi alternator. Not all auto elecs do rebuilds now a days as it's simpler/cheaper for them to replace. Try an 'old time' auto elec or one that does trucks and or farm equipment as they are more likely to still have/ use these skills. :)


Deano :)

Quote:

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Originally Posted by dado.mago

Hi mate, I am just experiencing no charge from the alternator :( I spoke with a friend of mine at the petrol station that has a workshop as well. He told me that if it was the brushes, if you hit the alternator with the hammer with the engine on, the light on the dashboard should blink (mine didn't). If not it's time to replace. Then I called a friend of mine how is an auto electrician in Italy and he told me that the alternator usually last 160.000/180.000km (mine is 165.000). He said as well that the regulator is the first thing to go. But my good news for you is this :D I don't know the year of your landy, so.... ....go here 90-110 & Defender Engine Electrics - Major Components at www.rimmerbros.co.uk and get the part number for your truck, then go here Alternator - Land Rover Part ERR6999 and insert the part code, then choose the manifacturer you prefer (this example is for Td5). Following the best-to-worst quality manifacturer: Bearmach-Allmakes-Britparts The first two are good, the third is **** :censored: Trust me, including the shipping you will end up to pay almost 50% compared from anywhere in Oz. For my case is 500$ all together. Cheers

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The engine is unique to Australia so won't have a parts listing in the UK.