battery warning light

Hi Guys
Quick question: My battery light came on on my journey to work. It was glowing dimly and started 2 miles into my 7 mile journey - traffic was mixed. Had a quick nosey but it all looked OK.
Coming home the same thing happened, nothing for 2 miles or so, then the battery light started glowing dimly again (volt meter showed normal charge) .Towards the end of the journey battery light came on full along with the oil and handbrake light. The volt meter showed 0. I switched off headlights and wipers etc and rev'ved it hard which returned it to just a dim battery light and a full volt meter.
When I got home I metered it properly and it was still glowing. 14.4 volts available everywhere except the battery warning exciter wire and the rev gauge terminal both showing 12 volts.
Its a Defender 110 300TDI - any ideas on if its the alternator/bad wiring or the diode pack?
Thanks in advance

Darren

Sounds like the diode are worn. Most diesel are robust when the power from the battery isn't great. Not the same with petrol though. I would have the alternator checked to make sure it faulty. Which end of Manchester are you. I am in North Manchester.
regards neighbour

Check the belt ,if slack or worn thin riding on the center of the pully it can slip giving symptoms described,especialy when under heavy load from lights ect.

i had this problem with my 300TDI, the battery warning light would glow dim, but i was still getting the correct voltage at the battery and the battery wasnt going flat
i eventually traced it to a faulty diode in the alternator. I replaced the alternator and also got a new pulley as they can be a right bugger to get off. Dont buy a cheap one get a decent one like a denso, the cheap ones only last about a year

Thank you guys will get it checked it is gonna be the diode though .

Oh and JNOAKES Im in East Manchester.