Topic: Cb550 electrical

[Houlie]

Hey guys, I’m trying to simplify the wiring on my brat style 1978 cb550. I’ve had a lot help from other posts on this forum and searched for my answers but I’m not sure what I am missing. I cannot get power on my black wire coming from my regulator/rectifier ( newly purchased).

I have:
3 yellow R/R to the 3 stator yellows
White R/R to stator white
2 green R/R to frame ground
1 green from stator to ground
Battery positive to on/off switch to 15A fuse to R/R red

My problem is I do not have switched power from R/R black. I had the bike running with what I thought was this setup with temporary wiring. The black was tied to my headlight (switched power) when this was set up.

My bike is kickstart only and  I have removed the rest of the stock harness. I have a headlight, signals, tail light and gauges. I have not  hooked up anything other than the headlight until I get this problem sorted.

Thanks,

[bryanj]

The black should be switched power INTO the reg not out so should connect tothe black comming out of the ignition switch BUT you need to check there is no volt drop between battery +ve and this wire or you will overcharge the battery

[Houlie]

Thanks bryanj,

I’ve switched the wires around I now have:

Bat positive to on/off switch to 15A fuse to reg/rec black

Using my text lamp I don’t have any power on the red reg/rec wire.

Thanks for your help. Obviously the electrical isn’t my strong suit. Below is the copied and pasted message from this forum in 2012 that I was trying to duplicate.

“ stator 3'y to 3'y rectifier
"white to volt reg white
rectifer green tied to volt reg green to ground
recitifer red an key switch red to battery positive 15-20 amp inline bus fuse
volt reg black pigtail to running light  further up frame pigtail to brake light switch- pigtail for coils  end of black to 3(off low hi) position toggle switch for headlight
second wire off brake light switch back to brake light wire
green off headlight frame ground”

[bryanj]

If red reg/rec wire is disconnected there will only be voltage if engine running BUT if you do that chances are you will blow the electronics as volts will spike high.
Red goes to bat +ve

[Houlie]

ok, so my red wire from my reg/rec goes to battery positive. And my black wire from my reg/rec goes to switched power. Is that right?

Thanks for your patience

[bryanj]

Yes if its wired as standard honda colours.
The black tells the reg what the battery voltage is and therefore how much charge it needs(which is why you need good connections at switch and bullets as if too much voltage lost battery will be overcharged) The red is rectifier +ve outlet to charge battery

[Houlie]

Thanks for the help. I got it wired up.