Alternator Issues

[BusinessConnected]

Hello:
Had the Dreaded "Red Battery Warning" come up on the "preferred" Discovery 3 (we have 3 of them).


I had a spare Alternator ordered from the USA around 12-18 months ago so I thought I'd fit it and see how it went..

Seemed to resolve the issue briefly.. however by the afternoon the Battery Warning Light was on and I was coming home on a Tow Truck again.


Took the Battery from another happily working TDV6 Disco 3 and placed in the car (thinking that perhaps the Faulty Alternator had killed the Battery previously) and the Car now started.. but Error Light was still on and had pretty much flattened the Battery in 1-2 minutes.


At this stage my thinking is that either
a) The Replacement Alternator is dodgy
b) There is some other electrical gremlin stopping the Alternator from Charging/Running.


I did see the Alternator running up to around 14.8V Yesterday when I'd initially changed the Alternator, when there was No Error Light.. so it seems it was working or delivering a faulty at one stage.


I've checked the 5A Fuse in the Fuse Box labelled Alternator and its fine.
I guess I'm just looking to see if there is any other thoughts/possibilities regarding the issue before I either


a) Purchase another Alternator from my Local Guy or
b) Play "Swapsies" with an Alternator from one of the other Discovery 3's
I don't really want to have to Remove/Fit it from another car if I can avoid it ;)

Thanks guys...

[PRS]

Your words:
"Took the Battery from another happily working TDV6 Disco 3 and placed in the car (thinking that perhaps the Faulty Alternator had killed the Battery previously) and the Car now started.. but Error Light was still on and had pretty much flattened the Battery in 1-2 minutes."

Given the replacement battery was even a half charged, something is seriously wrong if it was flattened in 1-2 minutes. Would have expected smoke.
You have also have two damaged alternators. Looking for the fault elsewhere, time for some serious checks.

Do you have a multimeter available?

Cheers Paul

[BusinessConnected]

Absolutely have a Multimeter and Nanocom available.
Only codes I'm getting from the Nanocom are the P0625 Generator Failure.

[PRS]

Was hoping your did not have a multimeter. The response then would have been to get professional help.

Already done the "lets throw parts at it diagnosis" and only damaged all those parts. Just too many things to address.
For example how sure are you of the replacement battery being OK. Suggest this was not checked prior to swapping. Hard to form a base line.

I refrain from suggesting installing suspect parts to other vehicle to check as this could cause further problems.

Suggest the faulty alternators be checked by an auto electrician as a first step. While there get the batteries load tested. Need to know what we are working with.

Paul

[BusinessConnected]

Paul:
The Battery was from another TDV6 2.7L Discovery 3 that has been running fine for 6+ months.. so I was fairly confident the Battery was ok.


I'm going to get into the nitty gritty a bit more and see what else may be the issue..

[BusinessConnected]

I also performed a 100A Load Test on the Battery with a "Battery Testing Tool" and the voltage drop was fine.. so I knew it was ok.

[PRS]

From your comments I must question the state of the replacement battery.
You say went from a good battery to flat in 1-2 minutes.
Assuming a 90A/H battery, even if there was only 20% of battery capacity used in 2 minutes this represent about 500 amp load. (90A/H battery x 20% = 18A/H = 18x30 for 2 minutes (30 times 2 minutes is 1 hour) = 540 amps).

Without smoke or some other huge load this leads to questioning the state of that battery.

How did you determine that battery was cactus? With a meter after/during the failure or what? Is there a very bad connection ??? and in fact the battery OK. Again just too many possibilities without accurate detailed information.

Hence, the previous comment of "need to know what we are working with".
Paul

[BusinessConnected]

Paul:
When I say dead.. I basically meant it was incapable of starting the car. Voltage went from 12.6 to 11.6V.


Anyhow I'll report more once further investigations have taken place.

[PRS]

If those voltages are "rested" measurements then 12.6 to 11.6 volt represents some 70-80% of battery capacity. Apply this to the previous post example. Look further into the battery condition.

[Graeme]

Was the previously purchased alternator the correct one for a 2.7 TDV6 and was it new or used?

Any auto-electrician should be able to test an alternator.

[Meken]

Mega fuse ? Doesn't that kill the battery if it's stuffed - basically like connecting terminals - which would explain the battery losing so much charge.
Also pretty sure unless you have a Traxide dual battery kit or condition charge the battery each week it's probably well below 80% soc being used in a disco

[Graeme]

A blown starter mega-fuse wont cause any damage to anything but the starter wont operate because of no power and probably also because its dead, being the likely cause of a blown mega-fuse.

[BusinessConnected]

Update:
Replaced Alternator with aftermarket from a client of mine in Sunshine.
Everything working and OBD2 reports live voltage around 14.7V

The original replacement was from AlternatorMan in the UK...
Unsure as to cause of its issues....