Help On Chevy Van

I have a 1987 Chevy C-20 Conversion Van. Both my power windows have stopped working. I checked the fuses and all were good. I checked and even replaced the switchs on the doors. Still no luck ,I took it to my local auto parts store and we plugged in a drivers side motor and still no power. I'm electrically ingnorant and need some help. I ask the auto store if there was a relay and he said yes. He advised me to call Chevrolet and get the part # so he could cross it over. I called and Chevrolet says the van has no power window relay. I need some advise on what to do.

Thanks,

TIm

Check to see if the following wires have power to them:

LF WINDOW UP/DN|dk. blue - brown    |A  |in drivers door            

The system is a type A which is like a (-) trigger door system. Check to see that the target wire has 12 volts.