Q: Intermittent and low speed wiper don't work fast speed wiper works 2014 Chevrolet Silverado 1500

Hi there - the lack of slow or intermittent motor speed can be caused by 2 issues: failure of the switches on the steering column stalk, or within the motor pulse control inside the motor housing. You’re going to need a voltmeter to check power to the motor for low speed to isolate this one to either the motor or the switch. I recommend an electrical inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.