[FED 387]

I recently replaced both batteries in my truck as they were about 5 yrs old and I was having a slow cranking situation in the winter--- truck still exhibited a slow crank speed after replacing the batteries--- went to start the truck today and all the dash lights /chimes/dome light went on just like normal ---waited for the wait to start light to go out turned the key and total darkness but dome light is flashing on and off and a clicking sound even with key removed from ignition coming from the left lower dash area---closed door still clicking--- thought maybe I had not tightened the battery cables properly so i cleaned both terminals and posts again re-tightened everything got in the truck and everything was normal all the dash lights were on power door locks worked etc.---tried to start and same symptoms as before---is it the GEM ??? or maybe the fuse box??? looked for moisture by the floor/fuse box area nothing, no wet carpet so does not look like any leakage anywhere--- anyone got any ideas??? Thanx FED 387