Don't blow your diode unless you like wasting money.
Do you have a basic multi meter?
Do you know how to check continuity?
Your tail cap most likely closes the case connection, but your momentary may well close your spring board connection.
That is one switch neg and one pos.
If you don't know how to check continuity of the wiring then I would not blow up my expensive diode.
Can you unscrew the host and see how it's wired?
If you are unsure then just wait, you waited to earn the money, you waited for the diode to arrive, don't blow it up now.
Do you have any pics of the host and it's innards?