Problems with power windows on a '93 Diamante

I am having problems with the power windows on my '93 SOHC 3.0L Diamante ES. It seems everytime I turn the car off the windows stop working for a random period of time. Sometimes I'll come back 30 min later and they start working again, sometimes longer. It doesnt always happen when I turn the car off though. It isn't only a single window switch, because none of the switches for any of the other windows work.

I am wondering if maybe something is wrong with the ETACS Control Unit, or if maybe something is malfunctioning with the window lock or something else.

This really has me stumped, any help is appreciated. Thanks.