The Stovebolt Site Forums The Shop Area The Electrical Bay Trouble switching from incandescent to LED taillights

I agree with bartamos, sounds like left and right rears are shorted together or wired together. I built my turn signal system using the three wire original turn signal switch. I am running single 1157 bulbs in the rear and single 1156 in the front. I added two DPDT relays under the dash. The turn switch activates a relay, one for each side, the original flasher can handles the job. All new wire to the rear and all original wire in the front.