It amazes me, but there is a fuse that power JUST the spark plugs. In nine years on here, I"ve heard of it blowing just twice.

If I were you, I"d check that fuse. Fuse 11 in the underhood (driver's side) fuse box in 2005 SRTs (and I think Limiteds - gotta be careful, they moved things around in the fuse box over the years and between SRT/Limited/Base models - make sure you look at the card under the lid for the right fuse).