MK1 headrest speaker wiring

I’m looking at replacing the headrest speakers on my Mk1 Eunos. Happy to upgrade fomr the original types having seen lots of recommendations to do so. However, before I purchase replacement speakers, does anyone know how I can confirm that the actual wiring is all OK (the wiring is present and connected to all 4 original speakers but I would like to check it will work OK with new speakers before I buy them)

Use a multimeter.

thanks. I can lay my hands on a multimeter easily enough but don’t have much clue regarding the use thereof. Can you advise what setting I should be using and what a good reading will look like?