Where is the auto shut down relay on a 1996 Plymouth Voyager lost the top of the fuse box under the hood?

When you say auto shut down relay (I may be wrong), but I am assuming you mean the inertia switch. On most all vehicles from the mid 90's have an inertia switch that monitors vehicle turbulence, the purpose being that if you are in a impact accident or rollover, it detects this and shuts down the fuel pump and spark to help prevent fire hazard and save lives. However they have been known quite often to trigger for no apparent reason, and then you get a no start condition. Location/ in most mini vans open the back hatch and mostly on the drivers side, but sometimes on the other side below the window area where the plastic inside molding on the sides are look for a access panel that pops off usually with a screwdriver. Sometimes you might have to move some carpeting. Look for a small box that has wires coming from it and a red button on it. If you find it then push the red button and it will reset the inertia switch and enable the fuel pump and spark to plugs. If the switch feels like it is not resetting then tap on the unit lightly with a mallot while trying to reset it. It should make a light click sound if it was tripped and reset.