Battery lite started flickering Sun.,stopped at Sears to have battery and alt checked.Diagnosed as a bad alternator.We were on a 90 mile trip one way,in the snow, when after 50 miles the dash lit up like a Christmas tree.I originally thought some wires got wet because of heavy snow and slush.Lites only came on for a split second and then went off,soon after I noticed Battery lite start to flicker.Turned off most of power acc and lite would stay off as long as it stayed above 2000 rpm.Stopped at Sears,they load tested and checked charging system and said bad alt.Found an Adv Auto Parts store and replaced it.Drove 90 miles back home no problem,2 miles away from home lites lit up again for a second.Started truck today battery was weak and now airbag lite flashes 5 times then 2 times after 2 or 3 cycles it stays on,I also noticed blower motor runs even with key off,stops when switch is in off position.I am going to rplace battery,I've been told bad alt could quickly ruin battery(battery could be old anyway).I hope these little glitches are battery related I know these late model computers are very tempermental.Truck is 97 Expedition E/B 5.4,could someone help with the possible code?Thanks Dave P.S. I have also heard Clicking noise from behind column.

 

The clicking noise is a good sign the battery may be going. How old is the battery? What brand is it?