2003 Expedition. In my hast, I took another vehicles battery to temporary replaced the dead on. Without thinking the terminals were opposite and sparked when hooked up. I quickly removed the terminal but I think damage was already done.

The radio does not have any power and my 4x4 select switch does not work or light up on the dash.

All of the fuses near the Pass. kick panel are good.

Everything else works fine on the vehicle. Where should I start?

 

Most radios have an in line fuse link to protect that circuit. You might get under the dash and see if it's blown.

You might also check the fuse box under the hood as your select switch might be fused there? Hopefully you still have the original manual for reference.

 

Did you test the main fuses on the firewall near the battery?