1972 XS-2 regulator / rectifier upgrade.

[wickermann]

I have been searching this site for info on converting my 1972 XS-2 to a solid state regulator / rectifier.
A used one came with my bike and I have started to install it.
It has 7 wires coming out of it, 3 white, 1 thick red, 1 thick black, 1 green and 1 brown.
I have been following a few wiring diagrams posted on this site and I found one that appears correct for my application.
I have connected the solid state regulator / rectifier as follows;
3 white wires to the 3 white wires to alternator, 1 thick red to the battery, 1 thick black to ground, 1 green to the green wire to brushes, 1 brown wire to the black wire to brushes. The wiring diagram I followed shows an ignition feed to join up with the brown wire. I rigged up a feed wire with a 10 amp fuse in line just in case. When I switch on the fuse blows immediately.
Is this because the brushes are grounded and need to fit nylon screws to un-ground them?
The bike charges fine as standard, I just fancy changing it to something a bit more reliable.
Any help greatly appreciated.
Dave.

 

[XSLeo]

Yes. On the 70-79 bikes the black wire brush ground to the stator housing as well as through the black wire to the harness.
So to properly hook up your new reg/rec you need to do the three nylon screw mods to isolate the brush from ground at the stator.
On my 75 I traced the black wire back up to the big plug where the alternator wires plug into the main harness. A few inches from this plug on the harness side I cut the black wire. I then hooked a brown wire to the black wire from the plug. I then ran this brown wire over to the brown wire of the reg, once joined there I ran this brown wire to power after the switch.
The stock reg and rec from the 70-79 bikes works ok. The reg being mechanical can be adjusted. Setting it so it charges enough at around town speeds it tends to overcharge at extended highway speeds. Get it set to not over charge on the highway and it undercharges around town. The up grade will cure this.
Leo

 

[wickermann]

thanks for that Leo. I have ordered some M4 x 10mm nylon screws from ebay. Cant wait to try it out.