1990 d21 ECM/ECU location?

[fedoraman]

I recently acquired a 1990 d21 with some electrical problems. It seem that the previous owner tried to install a fried amp and did some damage to the ecu/ecm. There is a white wire coming off the batter that heats up upon trying to start the truck, the fuel pump is fried, and I'm pretty a couple of relays got hit as well. I need to know where the ecu/ecm is located, any help would be greatly appreciated.

[Midnight Tech]

It should be under the passenger seat.

[fedoraman]

I appreciate the timely response. As I predicted the board of the ecm/ecu showed severe damage. I am now on a search for a cheap ecm/ecu, any help would be greatly appreciated in this venture as well.