Sounds like there may be an issue with the wiring from the relay to the window regulators since you have 12 volts to the relay. You can do two things,replace the relay and see if they work and it that does not solve your issue then check each window regulator to see if they are working,to do that you have to remove the door panel and look for a green and a black wire that runs from the regulator motor and run a ground to the black and a hot wire to the green and see if that works if they still dont work then you have bad motors.