get a free alternator check at any half decent garage or even a trade alternator place before you "splash the cash" (even halfords might do a free check?)
Looking at my screen it looks like you are only getting 14.5 volts at 3000 revs but my amd chip may be lying ;)
You can't check an alternator functionally with an ohmmeter without dismantling it as the phase windings effectively bridge the diode pairs, masking the effect of an open circuit diode.
A voltage check is useful, but if you have a whining noise which is non-mechanical in origin, this generally indicates a diode fault. The machine becomes magnetically noisy with a faulty diode bechause the phases are no longer balanced. The diodes can indeed be checked with an ohmmeter, but you must disconnect the stator first.
I have seen a few Valeo machines of this vintage with faulty stators - the windings come out of the slots, are hit by the rotor and then break and/or are grounded. This will be obvious if you dismantle the machine - remember that Valeo stators are not self-centering. This fault also gives magnetic noise due to phase imbalance.
MINI has revised the Countryman with slight tweaks to the exterior styling and improved engines for better fuel economy. The revised car is priced from £16,990 and will be available to order from June.