There are numerous bullet type connections involved and the left handle bar switch itself which usually need a good cleaning. Solder connections are often loose particularly in the switch. Sometimes they need being cleaned/replaced and re-connected with di-electric grease. As well.....if your bike is so equiped, the turn signal self cancelling unit often has become trouble prone and a source of unreliable operation. The TSCU is often discarded which turns the 3 prong flasher into just 2 and much less costly to replace btw. A good cleaning, re-solder if indicated, re-connect with di-electric grease often solves reliability issues.....like dirty contacts/connection issues made worse being wet are more often failure causes than a bad flasher per se. Blue