Replace the break sensor on my Hyundai 2001 300xg lights still not working plz

Going to try checking the wiring ASAP but bulbs are new. A repair shop try to tell me I needs a brand new fuse box but how is that when all lights but break lights and and dash lights don't work?

If your handy with testing equipment then you need to get wiring diagrams of your brake lights and see how they work. Most likely it goes out the brake light switch to a fuse then from there it feeds your brake lights. You need to see where the power stops. And if the brake light switch has power. Sounds like you could have a different fuse that blown that feed your dash lights and brake lights. Check all the fuses with the key on with a power probe of test light.

So is there a such thing as me needing a new fuse box if all lights but the break lights work? Thank you for you help I'm going to try it all.

Well the brake lights should have there own fuses and it could have a bad fuse box. Chryslers have that problem a lot with there fuse box, ford expeditions have a similar problem with there fuse boxes also. It's not to much that it happens but it can. Call me at 760-529-4286 (cell) if you would like me to take a look at it