Alternator wiring

I am planning to upgrade the alternator on my 1991 Santana Samurai from 45 to 70 amps.
It is appreciated this will not be a simple "plug and play" operation.
Existing wiring is as attached picture. Does not match up with information from wiring diagram information I have.
Advice appreciated on how to go about checking wiring runs. Thanks. 

Found this wiring diagram which seems to suggest there are only 2 wires, yours looks like more, but they could just be doubled up.

Wiring Diagram

The larger of the wires go direct to the battery, the smaller I suspect will just go through the ignition warning like, what connections does the new alternator have?

 
Thank you for your response.
New alternator will have connections as in picture attached

That is a Nippondenso alternator.
The correct waterproof plug is about a million pounds,
e.g. store.alternatorparts.com/c1850-denso-ro...epair-connector.aspx

but you can bodge something with the correct size Lucar clips, or get one out of a Toyota- try and get as much of the loom as you can, it saves buying wire...


Wiring should be
 



No idea about your current wiring, most likely the warning lamp is white with red trace.


 

 

Thank you for the additional information.
Have located a Denso connector on ebay which I plan to try and use.

The samurai usually got the green round denso connector when new.
My older 84 SJ 410 did not have one so when I put the newer alternator in it I just used the std spade connectors.

Was planning to splice in a denso plug, but the spade have not fallen off yet so maybe later.

I’ve just fitted an alto like this to my SJ. 
The big change is you need an ignition live to the ‘T’ plug instead of it being all just lives. Fly lead from the coil will do it…