Following on from the thread I put up about alternator ...

I went out to my l322 to find a dead battery
I charged the battery up started it and and saw battery voltage was showing only 11 volts or so while engine running.

I checked all the obvious things and came to the conclusion the alternator was dead...

I pulled the alternator out and bench tested it and found its actually putting out 14v.

Ive put the car back together- the battery is less than a year old, is an AGM type and is holding charge

When the car is locked up the battery holds charge as soon as I unlock the car the voltage drops to 12.3v within a couple of minutes.

Even if I connect an external battery charger feeding 3.8amp's directly to the battery the voltage drops from over 13v to 12.3v within a couple of minutes of unlocking the car.

What could be causing such a massive drain on the system??

Any suggestions i'm very greatful for

thanks guys

It will drop due to various systems booting/initialising then should recover. Your focus from my experience should be the charging system which should be @14.5~7. Clean and tighten the terminals (make sure there is very little resistance) reset battery. If this improves the charging then alternator is good, if it is flakey then you have bad contacts in the circuit.

good luck!

also a BM2 type device is handy to keep an eye on the battery SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

Hey dude , your 100% I pulled off the heavy duty positive lead that runs to starter and alternator and it was giving 1v or less with engine running ,

I’m back to thinking the alternator is faulty.

The only problem I have is that the alternator was giving me 13.8v charge when I spun it at 3000rpm with 12.6v to the signal feed on the bench.

But now it’s back in and it’s not doing anything .

So I’m now back to thinking that the alternator either isn’t getting excited from the ecm.

Think I need to pull the alternator out and give a 12v feed directly and see if it’s then giving out charge ,

I’d be delighted if it was just an alternator I need to replace ,

Thanks so much for your help

have you checked if that cable has a short to ground? After the reinstall pls reset battery and check. SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

Cable is sound , no continuity to ground

I learnt the hard way but spending a bit of time around the battery and all the breakout there is certainly worthwhile also. I removed all the mega fuses and cleaned, found oxidation and one loose nut on the high current busbar behind battery.

 SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

Here’s dude , I’ve dropped alternator off to specialist to check , hopefully he will say it’s duff , and it will be the end of my problem , otherwise it’s back to the drawing board !