Quoted from jj44114:
They should be wired in series, they are now wired in parallel which gives 4 ohms to the amp. Might have blown the audio amp.
The parallel wiring in that picture on those speakers looks factory. The TDA2002 amp is designed to drive loads down to 1.6 ohms, so a 4 ohms load isn't going to blow it. Remember the speaker load is hanging off the 100 ohm wirewound volume pot anyway so under normal circumstances the amp won't see a load that low.
OP, are you reading 100 ohms at the output of the sound board no matter where you have the coin door volume set?
When the coin door volume is at max volume position you should read 4 ohms. When the pot is at minimum volume you should read 100 ohms. The resistance reading should change as you adjust the volume.
If you always read 100 ohms no matter where the volume pot is positioned, it says you've got an open circuit between the volume pot and the speakers, or both speakers are open circuited (unlikely for two of them to go but still possible).