1996 Plymouth grand voyager se-need diagram showing where body control module would be located.

The BCM is located on the drivers side under the the steering column. It is behind the fuses and to get to it you have to remove the bash board plastic, than a pice of metal and than you have to remove the fuses box. It will take you approximately 20 min to remove everything. Once you remove the BCM you need to take note of the Part Number P/N. It has to be the same P/N on the replacement BCM. You can use any BCM from years 1996-2000 but make sure the electrical configuration is the same as yours (Power windows, alarms, etc.). I bought my BCM on the junk yard for 35 dollars and my car works perfectly.
I hope this may have assisted you,
Tom