Whirlpool wont fill & agitator just spins

Frigidaire (GLSW179AS4) top load washer goes straight to rotating the agitator when turned on to any wash cycle, without filling with water.Faucet’s have water supply ( hot & cold)available. I tested the voltage to the water valve & only get 15.0 vac when I first turn the cycle switch on ( to any cycle)for several seconds, then it drops to 2.0 vac.Problem occurred overnight, was ok mid week/ not ok today.Agitator does respond to different cycle speeds ( norm’/gentle’).
Thanks P

I think you have two potential suspects, the timer and the water level switch. I would check the tube from the water level switch, and if it is ok try changing out the switch. If that don’t do it, the timer is the next logical place.