I am trying to help a neighbour (87yo). His 1974 620 Ute had a flat battery. When we recharged his battery the parking lights came on without reason. He is a retired mechanic, and understands circuits. He pulled the light switch apart, cleaned it and reassembled it. While ever the battery is connected the parking lights are on, and he is at a loss as to why. I have searched other posts, and there seems to be confusion around brake lights and parking lights. I am specifically looking for information based on parking light faults. Any suggestions please?