Tried searching existing posts a couple of times but couldn't strike the right nerve. Airbag light came on steady, not blinking; #2 10 amp fuse blew. No heater/ac blower motor, no back up lights, no o/d on-off light.
Replaced fuse. OK for a few days and fuse blew again. Turned airbag off with key, replaced fuse so I could at least have heater fan, back-up lights, etc. Fuse blew again.
Now I'm really thinking hard. What circumstances surround this? There were two: coming through standing water creek crossings in 4wd drive high range; had passenger in truck on first occasion. Other occasions no passenger but crossing shallow water and engaging or disengaging 4wd. Took it to dealer. He couldin't get it to replicate, and tried putting passenger in truck also. He put in a new fuse. I drove it about 3 days, fuse blew again after crossing water and engaging 4wd.
Took it back to dealer. More diagnostics, and dealer replaced 4wd shift motor with my OK. Total damage $674.00. Picked up truck, no problems for over a week. Went to grocery store, did not cross water, had a box of deck screws on passenger seat (about 3 pounds or so), came out and put a 12 pack of soda on passenger seat, fuse blew.
Called dealer and got another service appointment for next week. I have enough faith in this dealership and their service that I have bought my last 5 vehicles there (all Fords, 4 new). Got this truck used at dealership with 63xxx miles, and bought extended warranty coverage too.
Dealer service mgr. said he entered part # for the 4wd shift motor and it was not covered under my plan.
Thoughts on any of this would be helpful. Sorry for the length of this post. Thanks!

 

This is for 2003 3.0l but will be the same as 4.0l

Looks like Fuse #2 powers quite a few things, best bet would be to unplug as many as you can and then put a new fuse in, then wait, and plug things back in one at a time.
"front function selector switch assembly" could be the heat control switch which is why heater fan won't work.

I would start with that seat.

 

Thanks for your reply. Proceeding logically beats the chaos of "try everything at once!". I'll look at the seat tomorrow and post what happens.

 

Seat and associated wiring under the seat is OK. The problem child was a frayed wire in the shift lever. Fixed and problem disappeared.

 

Good work in tracking it down

Thanks for posting the fix, will give the next guy a place to check