What does fuse #38 do? It keeps popping like there is a short?

Looks like it is the power supply for several sensors and the PCM power relay. Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

What is next -What is the actual procedure to troubleshoot. Fuse #38 keeps blowing did remove the oil pack and ignition transformer capacitor no signs of ground short . Primary coil on coil pack around 1 ohm one of them around .8ohms. Secondary all checkaround 13.3 Kohms . My ford explorer is 4.0L 2004 XLT. I run out of options.

Fuse #38 goes to the heated oxygen sensors which can short out, I would unplug the sensors and replace the fuse to see if it still happens. here are the sensor locations so you can check it out in the images below. Please let me know what happens.

My 2004 Ford Explorer is different, see the attachment and you will notice the location for F38 and its path. I had removed the ignition coil the capacitor and F38 keeps blowing trying to upload Xcel or Pdf files and it doesn't work.

They must be an image file.pnp .jpeg or .gif I found a wiring diagram that shows it going to the differential pressure feedback EGR and the EVAP purge canister valve, please unplug these one at a time to see if the fuse blows and let me know.