regulator/rectifier -stator plug

Hello All: My question is on a 81 kz750 that I have wired bare bones. The plug from the stator to the regulator has a black and a brown wire & of course the 3 yellows. the black seams to be hot/ I thought that it was a ground. please help with what I am missing. I put my voltage tester on it and it reads 38+ when the brown sensor wire is not pluged in and around 12.3 when the brown is pluged to a hot lead. Can someone help me understand whats happening.

Do you have a wiring diagram? For the stock wiring harness the brown wire acts as a sensor wire for the voltage regulator & it is basically a hot wire. The voltage regulator circuitry detects the voltage from the brown wire to determine whether or not to continue charging the battery.

R/R -->> battery -->> Ign Switch -->> brown wire -->> R/R.

Assuming the bike is a 750-4 E or H, there should be 3 yellow wires coming from the stator. The voltage from those wires, testing in pairs, should be about 50 VAC @ 4000 rpms (set meter to AC ---- alternating current). The voltage regulator should also have 3 yellow wires, a black ground wire, a red/white power output wire, & a brown sensor wire. The red/white wire supplies DC voltage to the bike & will be connected to either the starter relay pos lug or the positive battery terminal.

Thank you, I understand the brown as a sensor and the 3 yellow wires from the stator. My main question is why is the black wire hot / showing voltage when it should be a ground?

Do you have the red/white wire? The black wire sends excess power to ground. When dealing with these it is critical to disconnect the black wire first.
Steve

Yes on the red and white. so the black wire is suppose to show voltage?regal ookbmi

Whatever that means. That's the excess voltage going to ground. Do you have a manual?
Steve

sorry about the letters after. new at this.

yes on the manual

Don't switch wires while it's running. Shut it down before testing. Connect the ground last.
Steve

won't the black wire short out if I hook it to a ground point

I bought a used reg/rect from The Old Kaw Man two years ago. I had bad connections at the plug and ruined it. I just bought another one last month. He sent me this.


Steve

Thanks I will get to the house tonight and give this a try. This helps a bunch, I am still a little worried about the black wire sparking when I touch it to any kind of ground.