Okay. Removed the original parking lights wiring and retired the parking lights. STILL had a double flash.

On a guess. I installed an LED lamp from a different manufacturer both are 1157. NO double flash. Everything works fine. I guess all lamps are not made the same.

Well now my truck is almost half way through a total rewire.😁

Don

Can’t begin to tell you how much I hate the name Stovebolt.