Battery going flat when parked overnight. One of two options. 1) Battery is faulty 2) If the Ignition switch is turned off and working properly, the only places power can go are through the regulator/rectifier or the starter relay. Most likely the R/R is faulty. To do a simple test, get a multimeter that has say, a 10 amps DC range. Make sure the meter leads are in the COMMON and 10 AMP sockets. Test the meter is working correctly by connecting the meter leads briefly to a good AA torch battery only. You should measure 2-4 amps on the meter. Make sure the ignition is off. DO NOT TURN THE IGNITION ON AT ANY TIME THE METER IS CONNECTED IN THIS MANNER. Disconnect the POSITIVE battery terminal. Connect the meter leads to the POSITIVE terminal and the DISCONNECTED red battery lead to complete the circuit. Do not connect the meter leads to the positive terminal and the metalwork of the bike or the negative terminal If you measure current flow go to step (A) If there is no current indicated on the meter select the next lowest DC current range. You will need to change meter leads to the low current terminals, usually marked COMMON and mA. If there is current indicated on the meter you have a fault in the bike. Go to (A) If there is still no current indicated then there is nothing draining the battery when turned off. You have some other problem. GO to (B) (A) Disconnect the Rectifier/Regulator at it's plug to see if the current drain drops to ZERO. If so the R/R is faulty. If not disconnect the big wire that goes to the starter motor. If the current still does not drop to zero consult an auto electrician for more advice. you probably have a shorted wire in bike somewhere or the ignition switch is faulty.. (B) Let us know how you get on...
