Possible causes for the open circuit are as follows. As the cause can exist in the connector/coupler or terminal, they need to be checked carefully.
When checking system circuits including an electronic control unit such as ecm, etc., It is important to perform careful check, starting with items which are easier to check.

|
Check each terminal visually for poor contact (possibly caused by dirt, corrosion, rust, entry of foreign object, etc.). At the same time, check to make sure that each terminal is fully inserted in the coupler and locked.
If contact tension is not enough, rectify the contact to increase tension or replace. The terminals must be clean and free of any foreign material which could impede proper terminal contact.

|
Locate abnormality, if any.

|
Battery
Continuity checkFront brake master cylinder / brake lever disassembly and assembly
Refer to “front brake master cylinder assembly removal and installation” .
Disassembly
Remove the reservoir cap (1), plate (2), diaphragm
(3) and reservoir tank (4).
Remove the brake light switch (5) and brake lever
(6).
Remove the dust boot (7) and push rod (8).
  ...
Precautions
Precautions for wheel and tire
Proper tire pressure and proper tire loading are important
factors. Over loading tire can lead to tire
failure and loss of motorcycle control.
Under-inflated tires make smooth cornering difficult, and
can result in rapid tire wear.
...
Cooling circuit inspection
Do not open the radiator cap when the
engine is hot, as you may be injured by
escaping hot liquid or vapor.
When removing the radiator cap tester, put
a rag on the filler to prevent the engine
coolant from spraying out.
Inspect the cooling ...