RE: What is this part?

["Frank Sperling" <sperling@hooked.net>]

It's not the flasher unit as some have suggested (the turn signals 
and the hazard lights still work when the unit is removed).  It's 
also not the inertia fuel shutoff.

Here's some more info.  It sits inside the engine compartment right 
below the fuse box just inside the passenger side wheel well.  Maybe 
this will help.