What could cause this to happen? I've checked the fuses and they are all good. Could it be the fuse box itself? Please help!

Replace the ignition switch, which includes a harness that plugs into the under dash fuse box and main harness--easy job. Disconnect the negative battery cable first.

Turn the ignition switch to ON and test for "power through the fuses," with a test light or multimeter. You will likely find some fuses where you don't have power. This should confirm problems with the ignition switch, since you know all the fuses are good.

Thank you, is that all it could be?

I think so. Ignition switches are high wear items, subject to wear, pitting, and melting.

Ok. Thank you

Let me know if this solves your problem.

Will do.