Be sure to pull the battery wire before you pull the instrument cluster - lest you short the ammeter lugs against the chassis and have free fireworks in the dash.
You can use a .22 cal bronze brush, in a drill, to clean your fuse contacts on an FJ40. I heartily agree with removing each fuse, being sure the metal caps aren't loose, and cleaning the fuse sockets, tightening them if necessary by bending the contacts.
Steve H. - KE0KNH
Colo Springs, CO
'78 FJ40, '89 FJ62, '98 4Runner