I bought the wrong 2003 f350 super duty 4x4 truck at an auction when i got the item #'s mixed up and bought the vehicle I was trying to avoid. The power windows, radio and instrument panel do not work. starts and runs fine. I went to the owners manual to start checking the fuses and saw that someone had made some notations re: PCM? I opened the hood and saw a fuse coming off the battery. someone has removed the relay 3003 fuse. the other fuses appear intact. I do not even know where to start.

 

This could be quite a mystery..

I think I would start out by getting an Oasis report and start building the truck's history.. Any chance you can speak with the former owner?

 

I am going to take a stab at starting the conversation. Since it is a 2003 with a 5.4, my wife has an F-250 and I believe the same fuse panel. I think that relay controls the fuel pump shut-off switch, PCM fuel pump monitor, Fuel Pump. So my theory is they jumpered the fuel pump stuff off the battery (since it runs). That is the simplest thing I can come up with. When the relay was in the box it was soldered in and is listed as a non serviceable part. The fix for others with R303 issues has been to replace the fuse box. I'll keep looking though.

 

Not sure in your case but the CJB (Central Junction Box) may have
an integrated relay that went south. You bets bet would be to get a
good wiring diagram for that truck so you know what is what.
That will also save you a lot of hair pulling.

Good luck with it. Also you might look on Ebay and see if they
have a Wiring Diagram Shop Workbook


Sean