Hi,
new here, I am trying to fit a 600w alternator upgrade to my 1976 T3 California and having some problems. Does anyone know if I can use original diode board with new 600w alternator upgrade kit.? The kit is supplied with a diode board but the wiring supplied appears to be designed for the diode to fit in the alternator cover as per BMW. Wires on new diode are very short and won’t fit through alternator cover grommet and is very difficult to find somewhere to mount it . My existing diode board is situated in RH side panel.
Am afraid that I may fry the diodes if I use original but am struggling to mount supplied upgrade diode.
Any advice gratefully received.
I understand you have sourced a 600W unit widely fitted to BMW airheads, where diode board is fitted directly over the generator, under the same cover. I am not the person to answer if diodes need to be any different to original ones to cope with bigger output, but looking for an answer right at the source would make sense - is it Motorrad Elektrik unit? If so, ask them, they speak English, they’re Americans:)
Thanks for the reply. It is an upgrade kit from Gutsibits . I will contact them next week.
Standard rectifier board rated for 20 Amps - 600W is more than double, over 40 Amps - so I would say no.
If it were me I would look at making the wires longer so they will reach? Assuming new rectifier goes where old one is.
Dare I ask, why are you doing this … 
I think you will also need to upgrade the regulator as it’s only rated around 13 amp.
thanks for the reply. It looks as though i will have to rewire the supplied boardand try and custom make a mount where the original was.
I am beginning to wonder why I stared but I thought it was a plug and play kit !
I had an alternator or rotor failure in France and thought it would be a good idea to replace the old original parts and I thought the upgrade would be helpful as I run running ligts.
Thank you for the reply.
I am beggining to wish I had not started this route but it seemed a good idea at ythe time!
OK then! Reminds me I had a rotor go open-circuit on the LM coming back from a club camp in Sussex or suchlike. Same trip, gearchange return spring broke! It would sort of charge provided I didn’t use any lights or indicators. Got it back home anyway.