Turn sig,fuel sending ghost??wth?

[dezdud]

Ok. So my gas gauge pegs over way past full when its full and shows 3/4 full when it's empty. The guy i bought the truck from put in a brand new gas tank and sending unit. When i put on my headlights,bright switch, the gas gauge slamms all the way to the left?? and seperatly, if i put on my left turn signel, the gas gauge needle moves back and forth with the signal, as well as my little red high beam indicator light going on and off in unisen with the signal??/ omg..wth? (the brights and turn signal do function though even with all that stuff going on)..????