F16-F39 - MCASE fuses (FMM). These are "slow-blow" fuses to tolerate a bit more inrush current - things like trailer lights, etc. The Littelfuse ones look different than whats in the truck. All three trucks used varying quantities of the 20A and 30A ratings. The 1500 trucks had 8 spare slots, the 2500 had 5 spare slots to fill.F16-F39 - MCASE fuses (FMM). These are "slow-blow" fuses t…