Turn Signal Troubles

Not sure what normal or electronis flashers means. Flashers do work. I will replace
All bulbs tonight. The front is an 1156. Only one fillament, not sure how bulb could be
Crossed feed. All test were done with parking lights off. Will check all few more things tonight. It could for sure be the switch. Replaced for testing a few years ago not sure if things have change all I know is left is acting weird now. If I don't have a bulb in rear should front be don'tng weird things like it does.