unknown alternator...

trying to identify the probably faulty alternator in my td4.. numbers on it are..
401354
02513206
103
done checks on it and it doesn't up the voltage when under load.. lights,fan,heated eats on.. drops to 12.4v, no load it goes to 13.6v, battery is new but needs a charge after 4 or so days.

looks like the regulator at fault, but cannot find the type of alternator, oh bugger!

Try aa drop test on the bat.., is the battery big enough for the engine? Halfrauds will give you a free bat/alt check 12-13 is a good charging rate from the alt..
Where did you test the alternator from? (Which terminals)

But the alternator should charge harder with the accessories switched on. The regulator has failed not the battery.

Yep the battery is new as I thought that was the problem initially (should have tested the original, but no time) so now have a perfectly good spare!

I had the voltmeter on the battery terminals at idle.. 12.9v, up the revs and 13.6 or so, switch stuff on and in drops right down to 12.notmuch v (all as per the Haynes manual)

The alternator looks fairly new compared to all the corroded stuff around it, just can't identify it.. maybe its just a cheap pile o crap!?!?!

Probably best to just replace the complete alternator rather than trying to do the regulator.

so its better to spend £100-400 on a new alternator than £15 on a new regulator?
I'd have to disagree with you there!

only problem for me is to try find just the regulator, I'm just going on the numbers I could see while its still on the engine.

Last time i had one reconditioned it was about 50 quid

Very few modern alternators have proper regulators these days. They use a charge control ECU. They also contain a current feedback signal so that engine ECU knows how much power is being drawn from the alternator.
Good luck with it.