brake shift interlock fuse

Unplug the shift interlock actuator, then see if another fuse blows. The actuator is located on the lower part of the steering column. It has three wires going to it; a black one, a red/light green, and a purple/orange. If the fuse still blows, the red/light green wire is grounded to something metal. If it does not blow, replace the actuator assembly.

I have made a mistake. Does it matter if it is a six cylinder which it is

Normally it is important to know the engine size and transmission type to look up the correct wiring diagram. In this case your van was only available with one engine, so I couldn't look up the wrong diagram.