I have a 1 hp water ace sprinkler pump, which is pumping out of lake, directly into the sprinker system. The pump is connected to an outlet which is controlled by a switch. Has worked great until today. The pump will run the sprinklers for about 7 minutes then turns off, after about 4 minutes pumps starts up again. Continues to do this until I turn switch off. Any help would greatly be appriciated.