Weak, poor contacts/connections in the iggy and kill switch are common.
That battery sounds like it's toast, The clicking is probably the solenoid as the voltage drops too low to hold it in when the starter motor is connected.
When you say cleaned it thoroughly , did you follow the guide and take it apart ? How long did you let it charge for ? ( you should have 13.5 V or so on a charged battery ) How about gasoline ? How old is it ? Lots of things to do when you are trying to wake one of these old bikes up . There is a checklist in the tech section .
Um you only put acid in a battery one time when it's brand new after that only distilled water goes in. Charge it,take the battery off the charger, check the voltage the next day. put a light load on it for 10 or 1 minutes recheck the voltage. Key on, stop switch off for 5 minutes would be a reasonable test if it's any good it should still have well over 11 volts. A weak or bad battery can destroy an MC charging system even if it does start.
Um you only put acid in a battery one time when it's brand new after that only distilled water goes in. Charge it,take the battery off the charger, check the voltage the next day. put a light load on it for 10 or 1 minutes recheck the voltage. Key on, stop switch off for 5 minutes would be a reasonable test if it's any good it should still have well over 11 volts. A weak or bad battery can destroy an MC charging system even if it does start.