Non-ELS lightbar as modkit part

Hello,
I am currently trying to make a non-els lightbar for a police vehicle which uses 2 sirens (siren1 & siren2) and extralight_3 (scene & alley lights), but as a modkit part for the vehicle so that it can be changed in a vehicle modification menu. I have got the lightbar onto the vehicle and all parts of the lightbar show up (inlcuding both sirens and extralight), however I cannot figure out how to get the sirens and extralight to work and after hours of google I still haven’t been able to find anything similar to what i’m trying to do.
hopefully someone is able to help to me

Below is the mod part parent and children
image