No low beam but high and driving lights work on 05 Impala

This is on a 2005 base model Chevy Impala.Today the wife was driving at 4 am and the reg. headlights worked fine,she kicked on the high beams,worked fine,but when she kicked off the high beams,the low beams quit working.No headlights at all unless you flip on and keep on the high beams......?...everything else...turn signals all other lights are working just fine.....no bad fuses that I can tell....don't have an owners manual so if there are headlight fuses I don't know to find them...don't see anything labeled for them in the inside right or left fuse boxes,.the inside headlights only work on high....but no outside lights on the headlight work at all.....hard to believe that BOTH low beams went bad at the same time....fuse...if so...where....relay...multi function switch...where do you start....?

ok hate to edit this way

Since the problem happened when she went from low to high beams and back, I'd lean towards a problem with the multifunction switch.

Either the headlight switch or the relay for the headlights. Had the same problem with an HHR and it was the connection on the relay prongs.

John

the headlight relays and fuses are in the under-hood fuse boxes. i have all fuse diagrams i can take pictures of as well as the owner's manual. Mine is a 2001 but the cars are the same from the 2000-2005 model years so it will work fine for you.