Hi all - hope you can help.
I thought I had a blown speaker in the left front door, but it turns out the issue is with the wiring. Both the woofer and the tweeter speakers aren't working there (and yes I checked by swapping to the right door).
I don't know what my next steps should be - can anyone offer any guidance?

Could be the amplifier output on that FL channel or the wiring.

I'd start at the audio output and check for signal, so the amp or head unit speaker output depending on your set up.
If that works then unplug the speaker wiring from the audio unit and check for continuity to the door.
Breaks maybe where the door hinges but not seen it. Also check connections to the head or amplifier, so the speaker lead connectors at the electronics end.