If you do not see the charge light dim, then you are not heating the glow plugs.

Contacts are down below the brake booster, and you can adjust the throw from the pull knob.

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