Alternator Failure

[Jamo]

My battery collapsed last week (12V to 1V in 200metres)

Today on placing a new battery in, I discovered that the alternator is U/S.

Seems the collapsing battery sent something back to the alternator that fried it.

If the new one arrives this week I'll install it this weekend and post pictures on how it's done for those who are interested.

[drivesafe]

Sorry to hear that, let us know how much too.

[Graeme]

Maybe the battery has an internal short circuit, which could easily have fried the diodes.

[Tote]

I had an alternator fail at about 8000Km, it was still half charging but the drivetrain computer had decided that it was dead and activated the battery light on the dash.
After the dealer replaced the alternator the light would not go out and they had to reflash the drivetrain computer to fix it. (after a week of r**ting around)

Regards,
Tote

[TDV6]

Sorry to hear of your battery falling over Jamo,

RE the battery sending a charge back and frying the alternator, I thought that the OE battery was a pyrotechnic type, that is, if it detects a short etc, it was to trigger the explosive charges under the battery terminals and isolate the battery from the car electronics, thus destroying the battery but protecting all the nice expensive puters in the car, once I was told about the battery I was extremely careful when connecting up to the charger.

Ryall

??? Just a thought, check it wasn’t the alternator stuffing up and the battery doing its thing as per design ???

[Jamo]

It was the tech and LR who told me about the collapsing thing. He said they'd had a couple do it.

It may have been the alternator first I don't know.

Either way, the smell plume of smoke from the alternator told me it was not very happy. Plus the new battery didn't self destruct like the other one did.

Note that they were/are LR OE batteries. Varta made in Germany. Good batteries. I don't see why it would need to destroy the battery to isolate itself. i would have thought that the computers would be fairly well protected from spikes anyway, but I could be wrong.

I'll see if the alternator can be repaired and keep it as a spare.

Things like this don't really phase me. I look at it as an opportunity to understand the car better and thus gives me more confidence when away from home.

[RichardK]

Things like this don't really phase me. I look at it as an opportunity to understand the car better and thus gives me more confidence when away from home.

Good thinking Jamo............I am the same, I feel it is necessary to understand these vehicles as I occasionally get into some pretty remote areas