Happy New Year!

I have a 2001 TAC-20 that had a card reader added for 2nd floor and they interrupted a wire at the button and it works okay with exception of phase-II fire service of course. Thought I could just pull in a relay with the 24volts from the micro switch to G24 and use dry contact from relay to make up connection but not so. Even tried adding a 3rd micro switch to the phase-II fire key switch but wrong configuration, I turn it to hold and relay energizes only to drop out again when in the on position. Spent 4hrs trying to figure this out and feel like an idiot, this shouldn't be that difficult? Any help or ideas greatly appreciated.

Respectfully,