> Can anyone tell me what's going on and what I should do?

For one thing, next time draw a diagram or take a photo before disconnecting anything.

As for what you have now, it sounds like you have power to the box and a switchloop in series with it. If that be true then you would most likely connect the light to the free single wires. You might want to test again, making sure the power is on and the wall switch is on.

Can you see what color the wires are, and where they come into the box?

Please post a photo if possible.

Thanks for the ideas. For the record, I didn't take down the chandelier and didn't have a chance to see or record how it was connected. As you may be able to see from the picture, there are strands of chandelier wire on each of the single wires, making me think that's how it was connected. I was concerned that the test light didn't change whether the switch was off or on. I got a multimeter and did some further testing, both with the old switch and with another that definitely works. Here are the results:
Old switch

Twisted to A On: 112 Off: 112

Twisted to B On: 68 Off: 70

A to B On: 24 Off: 24

New switch

Twisted to A On: 114 Off: 114

Twisted to B On: 0 Off: 69

A to B On: 114 Off: 25

Looks like it's A to B as I suspected. What do you think? Do I need a new switch?

Brian

Problem solved.

The two bare wires were the right connection. It worked with a plain switch and not with my dimmer switch. A new dimmer switch is in and working just fine. Thanks for all the help.