Topic: cb750 K8 ignition switch aftermarket? (pic) br and br/wh are dead

[Rddmm2]

On my 78cb750K, 2 brown and br/white are dead - yet Red is hot to switch and blk is ok/hot.
NOTE: I recently replaced an old fairing and so replaced signals and headlight with NOS.  I unplugged the round ignition switch and cleaned it up and seems in good shape and I cleaned up the rectangular 5 pin plug. (see pic) Is the switch housing and white contact portion both aftermarket parts? and is 5 pin rectangular plug aftermarket too?   any suggestions as to whether I should replace the same aftermarket part or look for an NOS switch would be appreciated.
Thanks.

[Ryan6838]

Looks like the bottom of the switch was replaced. I need to replace mine. Parts n more sell them https://www.partsnmore.com/cat_index.php?model=cb750_sohc&category=electrical    Other then that i dont know alot on the wiring side.

[Nikkisixx]

Is the switch housing and white contact portion both aftermarket parts?
and is 5 pin rectangular plug aftermarket too?

Looks like it has been replaced (usually turn yellowed/brown with age), but that is the stock configuration and wiring. 

   any suggestions as to whether I should replace the same aftermarket part or look for an NOS switch would be appreciated.

I bought replacement parts from Parts-n-More and it went to sh@t in just a week. It is now held together with JB weld. Another member that lives here in Charlotte also bought an aftermarket piece and it is grouchy as well.  Is yours holding up?  If not, that is three strikes.  I will replace mine with NOS when I get around to it 

[Bodi]

Dead?
make sure that it's not normal. The tail light is a weird circuit. In "park" power is switched from the red (main fuse power) wire to the tail light - the brown wire.
In "on" the brown/white wire connects to the tail light brown wire. The brown/white wire is power coming from the TAIL fuse.
the circuit goes something like
battery "+" - main fuse - red wire - ignition switch BAT terminal to ignition key switch:
park: RED to BROWN, tail light on. No other connections
off: no connections.
on: RED to BLACK ... black is ignition switched power and goes directly to the coils and charging system, plus to the HEAD and TAIL fuses.

wiring is (for the tail light) black - brown/black (tail fuse power, connected via a splice or through the headlight switch if it has an OFF setting) - tail fuse - brown/white (TAIL fused  power) - ignition switch again - brown (tail light power).

[Rddmm2]

Thanks. I worked on premise that if nothing shows up on Brown or Br-Wh using a 12 v tester right at the bottom of the switch in 'Park' or 'On' position, I figured that means there's a problem with the switch no matter what.  However, I'll use your circuit info and look at it again. 
thanks for confirming the aftermarket part and good source - Unless I discover something else, I may just order the bottom half of the switch and hopefully its a quick fix. 

[Bodi]

Sounds like a bad switch, the tail light part of the switch has probably fallen out. Within these silly switches there are tiny metal widgets with near microscopic springs that get shifted around to make contact between little metal bumps. If somehow the bottom case gets pulled open a little bit, one or more of the metal bits or springs falls out.
Solution: get an automotive key switch and kludge it in place. This will only have BAT IGN and START terminals. You will lose the parking light function that maybe one in a million riders has ever actually used. Red goes to BAT, black to IGN, nothing to START, and you connect the brown/white and brown wires together. If you want to get fancy you can wire the starter to the start terminal and have key starting like a (old) car.
(old because the new cars I've seen recently don't even have an actual key or keyhole, nor do some of the new bikes)