Whats this wire and what does the diode block do?

Got a white wire comes from the bottom of the motor white in color runs up with the 3 white alternator wires separate from them but the same path. Is this the neutral wire? Also what is the diode block do? see a lot of wires heading to it and I am uncertain what this does. Trying to figure out the very minimum wires to hook up to see if I can make it run. I think I would only need to supply positive volts currently that will be red/white wire going to the ignitor unit and battery ground to the black wire and hook up the coil wires.
Can some one tell me if it will hurt any thing not hooking up the alternator and R/R just to see if it will fire up?

 

Which XJ?
Please add that information to your signature.

 

xj550 maxim, Its a white wire all by itself comes from the bottom of the motor. I was also wondering what the diode block with the 7 wires do.

 

there is a diode and resistor set up in there for the oil light test
as well as other things it controls
different bikes have different diodeblocks

 

xj600 diodes
View attachment 25959 top diode near 11 is for neutral switch and light #21
third diode down is for oil light setuo #21

 

This is handy but I get a message saying -
The requested attachment could not be found.

 

this is how wiring dia shows diodes

and this is how they are on the bike

 

Amazing that it does all that. I dont think Im going to include one in my build. Im cutting weight.

 

so your plan is to remove the relays as well? diodes control relays.

 

Not a lot of electrical weight on a motorcycle - maybe a diet instead?

 

or a mac 4 to 1 exhaust instead of stock about 20 pounds lighter

 

Yes Ill probably just have the minimum wiring job, I am thinking of leaving blinkers in this one. Ive got a 76 xs650 and it only has starting, running and charging wiring.