Alternator Failure?

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Originally Posted by Meken

Yes why can't an inline fuse be installed at the connection of the cable to the alternator? Seems the logical fix - then again will an internal short blow a 200amp fuse?

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I considered fitting a fuse in the existing cable but then decided it wouldn't be a good enough spot exposed to mud and water and difficult to fit in the first place, most likely requiring the alternator to be removed to disconnect the cable so that terminals can be fitted.

An short circuit of the diodes in an alternator rated at 180A may require an even higher rated fuse than 200A (because at times it may exceed LR's specs) so I have acquired a 225A fuse as backup. With the 3.0's alternator's internal wiring capable of sustaining 180A output, a short circuit caused by 1 or more of its Zener diodes reverse conducting (due to age & load induced fatigue lowering its trigger voltage, originally around 30V) should allow more than 180A to flow. A quick check of the fuse in the Territory against its alternator's rated o/p would confirm the required fuse.

Thank you everyone.

Your help has been just what i needed to know to know what is needed ;-)

I have ordered the alternator through Ashdown Ingram and as such it will be a OEX unit.

I will put it in tomorrow night or Saturday morning.

I will keep you posted.

Thanks again, much appreciated.

Carlos

So,

Overnighted the alternator from Ashdown Ingram from Perth.

Went about the removal and replacement. I did not remove any hoses only two bolt/screws that were holding the coolant pipe that passes in front of the alternator. This gave enough room to wiggle the alternator past. I did have to turn the viscous fan bolt clockwise too. Anyhow, I try to put the belt back on and bam-bow. Six rib places not eight. Lucky I thought to tackle the job tonight so I can see wether I can swap the pulleys over somewhere tomorrow morning. Very disappointed indeed!

Also the alternator casting is not as neatly done as the denso and is rated at 150 Amps not 180 Amps as described somewhere here....
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It looks like you were wise enough to look at the pulley before you installed the alternator. Most end up wondering why what was a perfectly good belt is later in tatters. In some cases, by the time they notice, the removed alternator has been sent back.

Normally the pulleys are just swapped and problem solved.

On my 2005 LR3, the alternator is rated at 150 amps and I think that is what most 3's have.

I think the D4 alternator is now 180 amps, probably what the alternator on the 3 should have been.

yeah,

The pulley changed right over and all was sweet. Charged the battery with a 25 amp charger and it bought it back from the dead.

The only problem now is that every few days the battery warning light comes on for less then a minute and today it came on three times and only when beginning to accelerate.

Could something be cooked?

Carlos

The odds are all is good except that the battery state of charge is still low.

The electrical system computers have some sort of emissions related accessory low power cut off cycle feature.

As such, you can never really trust what the regulator and the engine computer is telling each other. Once upon a time, regulators told the alternator what to do based on battery voltage and some would even instruct the engine to speed up a bit at idle; now the engine computer tells components such as heated seats, radio amplifiers etc to shut down or cycle, and tells the regulator to minimize alternator output and suck instead from the battery. What this effectively means is the battery never gets fully charged no matter how much you drive.

As such, at least twice a year, for about a week at a time, every night I connect my battery, (actually both battery's), to my CTEK charger.

It seems to take a week of nightly charges on each battery to get them back up to where the CTEK is happy.

In other words, while there might be something wrong, first just try a week of battery charging at a low charge rate.

So your saying that it might be related to a low battery charge?

I thought it meant there is a fault with the charging system?

We have found that the battery does start the car slower and slower over time - 1 year. Sounds like the top up charge is a good way to go though.

I would say there is a lot of debate about what the red battery light illuminating on the dash really indicates. As with all things LR and electrical, there is always much discussion.

Myself, I think LR in their desire to be on the cutting edge of design back in 2003/4, got too smart for themselves.

The PWM regulator design within the alternator is now only starting to get common on new vehicles and then add that common starter and alternator cable to the design, and you have added alot of variables when bits start to weaken.

There is nothing really wrong with the design when all is brand new and working well, it is just as parts get older that the potential variables start to create problems never seen before.

Anyway, a fully charged battery has solved many strange electrical problems on the 3. If you purchase a new battery, same thing, charge it for a week on the vehicle after you install it.