If it does not work from the manual switch I would check the bulb, fuse and manual switch in that order.

If it does work from the manual switch the possibilities are the door switch or the manual switch, or human error by leaving the manual switch in the third position (disable).

I'm not sure what model you have so this is generic information, but if it is the door switch you have two of them and it is highly unlikely that they would both fail simultaneously, so if it lights with one door open, but not the other you have a bad door switch...

I find my manual switch in the disable position from time to time and wonder why the lights don't come on when I open the door...

Good Luck!

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