First, verify fuse is good. Best to swap it with a known good fuse. A fuse can fail to pass current and still "look" good.

Then, check starter neutral switch, it's mounted on the side of the tranmission, left (driver's) side.

Jim

__________________
14 E250 BlueTEC black. 45k miles
95 E320 Cabriolet Emerald green 66k miles
94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles