Hello all could use some feed back.
Engine off key on ,stop /turn signal work perfect, engine on with right signal on I loose my left brake light only , wireing all seems untouched. HELP !!
Welcome to the site. I'm going to tell you what you already know - I just don't see the logic to what is going on with your signal, and I've spend a couple of DOZEN hours on mine.
Best I can say is, focus on the 'doesn't work' part, use a multimeter or test light and the schematic and start at the fuse following every point in the schamtic.
It's time consuming and it sucks but it never lies and never fails!