if youre talking a valotage regulator it should have an constant o/p from it at any engine/alternator speed of around 13.7 volts. If it fluctuates try to adjust it but if its a mechanical one it means its noisy and you should do away with it and the standard Hitachi alternator. Get a reco bosch one from I think a KB laser (straight bolt in). Only need to connect 1 wire and it has an internal regulator. Make sure the internal reg is genuine bosch as aftermarket regs such as ingram and ashown ones arent much chop. Should cost u all up no more than $150 and all probs will be solved.
If youre in Sydney you can call hornsby auto electrical (Chris and Doug) or Jacks auto electrical in Artarmon (Jack)