TOPIC:

Why do you want to replace the switch? It would probably be much easier to get a new key, assuming it is a factory switch.

THE BROWN IS WITH THE YELLOW,BLUE,AND RED.(ALL 4 GO TO SAME POST. THE WHITE IS BY ITSELF. SO I THINK I GET THAT AND THEN ONE MORE THING. THERE ARE 3 WIRES THAT I DONT KNOW WHERE THEY WOULD GO. SO UP FRONT THERE IS THE START SWITCH THAT I SHOWED AND THEN THERE IS A TOGGLE THAT HAS 2 POSTS AND THE ONE HAD A  (RED w BLACK STRIPE) WIRE CONNECTED COMING FROM HEADLIGHT.

BUT IM NOT SURE WHERE THE OTHER (RED w YELLOW STRIPE) WIRE COMING FROM THE HEADLIGHT WILL PLUG INTO? ASSUMIMG IT NGOES TO THE OTHER POST ON TOGGLE.?
AND NOT SURE WHERE THE (BLUE) WIRE SHOULD PLUG INTO. iTS COMING FROM THE HARNESS SOMEWHERE WHICH. IT GOES:

BLUE WIRE COMING FROM HARNESS < THEN SPLITS INTO 2 WIRES !)RED WIRE GOING TO ODOMETER 2) BLUE WIRE WITH END ON IT AND THIS IS THE ONE I DONT KNOW WHERE IT GOES TO( IT LOOKS CLOSE SITTING NEAR TOGGLE AND THE IGNITION) HOPEFULLY THIS MAKES SENSE.

THIS IS HOW I GOT THE BIKE AND I JUST WANT TO GET IT STARTED BUT DONT WANT TO FRY ANYTHING AND I DONT HAVE THE MONEY TO GO BUY ANY PARTS. THE ONLY REASON IM CHANGING THE IGNITION BECAUSE THE GUY THAT SOLD IT TO ME LOST THE KEYS. AND THAT NEW IGNITION I ALREADY HAD. ITS JUST TEMP!!!

THANK YOU SO MUCH FOR YOUR HELP 

When you are ready and if you want to use the switch that came with the bike, a locksmith can make a key for it.

Also, based on the frame number on the sticker, that is a 1975 KZ400S. Be sure that you refer to the correct wiring diagram as there are small differences between the various 400 models.

If your short term goal is just to find out if it will run, it might be easier to skip all that jacked up wiring, and just run the bare minimum wires to run the ignition. Then if you want to fix what the po did to the wiring, you can chase down all the “custom” bits and remove them. It will require some patience, but it is not as complicated as it looks. If your long term goal is to build some sort of stripped down bike, then one of Lou’s bare bones systems will work a treat.

Ok, that makes more sense...the brown being connected to red, yellow, and blue.

When describing a wire with two colors, you mention the main color first then / with the stripe color second.

The blue wire could be to power the gauge lights or the headlight or both.  The brown wire, on the stock bike, would eventually power the yellow/red wire which powers the ignition system. The yellow/red wire gets power from the brown wire then feeds that power to the positive side of the ignition coil.  There should be an un-related blue wire going from the negative side of the coil to the points.  As long as you have all of that, the bike should run on battery power.

The red/black and red/yellow are for the high beam and low beam of the headlight.  Those wires get power, one at a time, depending on the switch position of the high-beam toggle.  It gets power from a blue wire, usually.  The blue wire gets power from the brown wire.  But since your toggle only has two connections, it can't be used as a normal Hi-Lo switch.  I'm not sure how they were using it.  It would need three connections to work as a normal Hi-Lo switch.

The brake light switches get power from the brown wire.  They switch that power to another un-related blue wire that feeds power to the brake light filament.

So as you can see, there are a few unrelated and related blue wires to keep track of.

 

It appears you have a S model.  I attempted to provide you with a wiring diagram for it earlier in this thread, but you did not want to down load it, so I created a version that can be displayed here you go. 

Hi..... I purchased a "complete" non-running KZ400 project bicycle. I purchased new start loops, tidied the entire thing up, got another start switch. all that works aside from the electric beginning and the horn. at the point when I kick it over with the kickstarter the focuses break the circuit like they are assume to. i'm getting 11.88 volts to the loops,, yet I'm getting zero force out the curl rolling to the motor. I have checked and twofold actually look at everything and as yet nothing. for what reason is there power going into the curl yet no force coming out. I know one issue that I really wanted to fix is that the curls are perusing 8-9 ohm and are assume to be at 3.2-3.7 ohms. how might I sort that out?