turn signal problems

When I turn ignition on both right and left rear signal lights flash. Turn right signal on, right front and right rear flash. Turn left signal on, left front, left rear and right rear flash. Tried new signal switch, removed ground on frame and cleaned and reinstalled. Checked all bulbs, checked flashers. When both rear lights are flashing, the power is coming through the turn signal and brake flasher. Anyone have a solution?

i would have to say try unwiring all the fuses and completly restarting. you may find a problem amongst the wiring maybe crossed or melted wires. my reverse lights didnt work because one of the fuses was loaded so i made an independent switch for reverse lights. try it step by step. disconnect different wires such as the left rear and see if the right rear still flashes. good luck