RIGHT NEW TO THIS FORUM STUFF SO BARE WITH ME ?
DOES ANYONE KNOW IF THE RECTIFIER COLOURS FOR THE 750 PASO ARE ALL THE SAME FOR UK SPEC BIKES AND USA ?
MINES A UK SPEC.

the original wiring colours should be the same, although if you look at the California Pasos's wiring, the two wires from the alternator are orange instead of yellow and at contact C there's a brown wire instead of a green/black one. If you have an aftermarket regulator it's possible its wiring colours are different.
What colour wires do you have? You can attach a picture to your posts.

Pls. don't type all caps, thanks.

File comment: reg

reg rec2.jpg [ 32.56 KiB | Viewed 7585 times ]
sorry about the CAPS, The after market reg is ok for the input from the generator usual two yellow and one red,
regulator / rec I have bought has two yellows two reds and black and white, black is case earthed and white prob' + output but means I have extra red mmmm?
tried to add a photo ? not sure it worked, man I'm rubbish at this .

Do NOT ground the black wire! On many aftermarket regulators the black wire is a voltage sensing wire. That is connected to any hot lead that has 12V at ignition on. It should be connected to a wire that has stable voltage with no voltage loss. If the wire suffers from a voltage loss (compared to the battery's voltage) the regulator will try to compensate by increasing charge which over some time will kill the battery.
The white wire is for the charging warning light.
The two red wires can be joined. Also install an additional wire from the regulator housing to an existing ground point.
To be sure: the red wire of the alternator is NOT connected to the red wire of the regulator.

- edited -

summed up:

regulator - original wiring
black - to ground
white - blue
red - red/black (not the red of the stator!)
red (join both red wires from the regulator)
yellow - yellow
yellow - yellow
red from the stator is not used
green/black from the bike's wiring harness is unused (isolate)

or

regulator - original wiring
black - to ground
white - blue
red - red/black (not the red of the stator!)
red (join both red wires from the regulator)
yellow - yellow (join both yellow wires from the stator)
yellow - red (from stator)
green/black from the bike's wiring harness is unused (isolate)

You'll have to see which of the two works. It's basically the same as described in these instructions:
https://app.box.com/s/r16ixjegwfl7aq3ybd0c

Ah man your a star i'll try that, just want it to be reliable and here in the uk weather can change quick so be using half decent connectors . Thanks again.

there's contradicting information about the black wire if you search online.
Here it says it is actually a ground connection:
http://www.tosave.com/p/Motorcycle-Volt ... 11247.html
Is that black wire as thick as the others or thinner and do you have an ohm meter?

If the black wire reads continuity to the regulator case it is almost definitely a ground wire. Connecting it to a switched 12V circuit will blow a fuse or burn something out.

I Derek that's what I was thinking, getting straight 0.0 ohms from case to black wire so direct connection, have had bike turning over, but not got the old carb back on yet so no real power out genny yet.
ive got another reg/rec coming from usa that's an electrix one or what ever its called but has better wiring info, 1st when I stripped bike I never took note of the wiring fitted to the old reg/rec due to working on loads of jap bikes spike here thought that the wiring dia would be spot on mmmmm, the output connector was burnt and the main head light connector, sure sign of over current.
2nd what a nightmare stripping the full bike down due to rust, but got it for a song so thought well 1st Italian bike in the stable so get on with it ya Tad!!!
cheers again spike.

Derek, it seems you're right. But if you look at other regulators tho the black is the sensor wire i.e. Electrex ESR540 or an original Ducati Energia regulator (pic below).
Also in the Electrex ESR510 instruction the black wire is mentioned.
Some regulators have a black ground wire, on others the ground wire is green.

paso750 the diagram shows a green wire as well must be the invisible one on the rectifier just not making sense, as I wrote to Derek the black is ground to casing, i'll await for the other reg /rec see how I get on with that, got loads of other things to do to the bike but getting there, tell you the visa is getting a kick in but hopefully worth it.
thanks again spike.

So in principle the green wire is just the same as the black as this is the negative earth through the bike ? the white looks like its the positive output to the battery, its just getting the correct connections into the loom that's bursting my peanut of a brain.

white to blue, double up the red then to + ,black to earth and i'll make a link from case as well, then simple yellow to yellow leave out the red from gen' ,Bingo !!! should be onto a winner. grand cheers again for the help.

it's either that or double up the yellow from the stator and connect those to one yellow from the regulator and the red of the stator to the other yellow of the regulator as per the Electrex/Electrosport instructions (first link posted). Since you verified that black is ground an additional wire to the case is not necessary.