Just wanted to put this up here in case it helps someone. I had a weak battery, it wouldn't take a charge so got a new one, the next day it was dead. Seems I had a short circuit somewhere, charged the new battery back up, and started the truck to make sure it was good, then it wouldn't turn off. I had to pull the plug to the coils to kill it. I started troubleshooting by checking the ignition switch, and PDU voltages across fuses, and relays, then went to the interior fuse box and started pulling wire connectors to isolate the short. Found water in the connectors and corrosion.
Cleaned up the connectors with WD-40 wire brush and reconnected.
Traced the water to a leaking antenna base (OEM replacement), disassembled and sealed it all w silicone then reassembled.
Everything is working fine now. hope it helps someone w troubleshooting.

 

Welcome to the forum

What year Ranger?

Never heard of antenna leak effecting fuse box, is it a 2004 -2011 Ranger with fuse box in passenger side kick panel?

Good info thanks

 

Yes its an 2004 Edge, 4.0, the fuse box is in the passenger outside footwell right under the antenna. It had a broken off antenna when I bought it and I replaced the base w an OEM base and antenna. I normally over engineer stuff and would have put down some silicone but i figured if that's the way it came from ford it would be fine. We have some torrential rains here and it must have seeped in and followed down the wires right into the connectors, didn't take much.

 

OK, yes Ford had a problem in a few vehicles with that location, thats called the SJB(smart junction box) and it is the Body Computer for the vehicle, also has the cab fuse panel.
Very expensive to replace the whole unit which is what a Ford shop would do.

Moisture came in from the windshield from the ones I read but antenna would also make sense

Thanks again