Blower fan for heating and a/c going on and off

The blower fan inside the truck blows just fine when you first start the truck but will cut off and not blow at all after a few minutes. Then it will cut back on after a minute or so. It does this off and on all the time. It seems if it were a fuse it would just cut off and not come back on. Any idea what it might be? Thanks for all help! This is a Dodge Ram 1500 Sport Edition.

The next time the blower stops working, pull over and reach under the passenger side of the dash and tap on the blower motor with the handle of a screwdriver. If the blower starts working replace the blower motor.

Tester

Thanks, I will try that tomorrow.