Took my bike to a garage the other day due to a fault that has been there the past 3 weeks. When the bike was idling, a multimetre was connected to the battery, it read 12.9v, yet when revved to 5k, it dips then stays at 12.3v, the diagnosis was given as my regulator needs replacing, Here lies my confusion; I was under the impression that a regulator, regulated, the volts, ie; set a limit for them, and it was the alternator that generated the power. By my logic the problem indicates a bad alternator as opposed to a dodgy reg/rec. Can someone explain it to me in laymans terms?
To much resistance in the regulator when it gets increased input from revving I would guess. But then I know nothing of this electrickery magic...
The reg rec firstly rectifies the voltage (converts from ac to dc) then regulates it. The voltage should increase to a peak of about 14.5v (give or take) at about 50% of revs. If there is no increase then there is nothing coming from the reg rec. The alt must be putting out something as your getting nearly 13v at idle. The alt only has one job, to produce ac voltage. The tell tale signs of a fooked reg rec are either no voltage increase, or a massive voltage increase as you pile on the coals. Ie its not regulating correctly. You can test the alt coils if you want for piece of mind, but id be very surprised given the results your getting.
I'd check all my connections/wires first! I changed mine(reg/rec) and it happened again on the cb. Pissed me off lol my mate came round cleaned the connections and it worked lol.
