Radio diagrams are here, 2004 had 3 options: Ford Ranger Radio Wiring Diagram
You will probably need a shop manual for 2004 Ranger, an EVTM(electric vacuum troubleshooting manual).
You can sometimes download them free, or buy them on ebay
You problem is most likely in the Smart Junction Box(SJB), that is where the fuses are in kick panel.
Wiper relays are in the engine fuse box BUT.........are controlled via SJB
All the power window stuff is in the SJB
Here are 2 power diagrams for 2004 Ranger