Regulator rectifier confusion.

[Bradley Adam Lay]

Heylo.

The skinny: I built a cafe racer, eitrd from scratch, burnt out two batteries.

I have a combo reg/rec purchased from Ricks. My bike is a 1981 xs400 heritage special. My R.R has 3 white wires, which I ran to the white wires on the R.R, 1 green to the magnet? A brown wire that is supplied with 12volts, a red to the battery, and a black to ground.

Now, with it wired like I just said it sends 19.8+volts to the battery (measurement taken from the red wire attached to the R.R while the machine is running), and with that same set up if i check the battery charge it dosent go over 14.8. My question, is that right? Because at one point (not now but the same day) I also took the ground from the rec reg and the ground from the magnet and tied them to each other, no other ground to earth and that gave me 13v at idle and above 3000rpm 14.8v but no change in the battery. I'm pretty lost here

 

[markmakeitso]

Hi Bradley,
Subscribed. I'm fighting a weird charging issue on an '80 SG, also equipped with a combo Rick's R/R courtesy of the previous owner. Sounds like we have similar wiring setups.
Your 19.8 VDC is alarming, as usually with a combined R/R you wouldn't have any DC voltages that high available for measuring. Do you mean 19.8V output at the regulator connector, but after going through the harness you only see 14.8 at the battery? 14.8 would be a pretty spectacular output, but that doesn't really mean the 19.8 is correct.

Your grounds jumping doesn't sound correct, and obviously doesn't match the wiring diagram.