Windshield Wiper/washer Switch problems of the 2000 Mazda B3000

The oil pressure guage has just quit working properly, it will not register when the truck is started, but if I hit a bump or stop the truck and turn it back on, or drive for two miles the oil guage will pop into normal range. The windshield wipers come on by themselves when switch is off, every time I make a right turn, during some left turns, and recently when I am slowing for red lights. The right front tire wore unevenly and caused excessive noise and bumpiness in the first 12,000 miles, it was rotated to left rear and now just makes noise. It was not a 2000 recall tire, but it seems to me that it has failed. (tiresize: 15)( dot number: tire size: 15 ).