You can check the genny but putting the tester to ac volts and connecting any two of the yellow wires to the tester- you should get at least 70V ac at 5000rpm. The gennies rarely give up so id say 99% the new reg/rec is duff.
The standard suzi shunt reg/rec is pants and not worth the ally used to make it, the best thing you can do with them is convert to the 2008 cbr6 f008 unit. Google SV650 reg/rec mod and you will see the same problem with the SV guys- same unit.
I had 4 go in 2 weeks until i fitted the cbr unit, now its 14.3v no matter wot! best mod you can ever do.