Hi Gals & Guys, So the first thing I had to fix back in '15 when I bought my 40k mile Ws6 was the rear driver side blinker/brake/running lights, two 3057 bulbs as y'all know I'm sure. SO, made it to this Inspection month and the darn finicky left turn blinker stays solid again (has worked intermittent in past year of infrequent Friday night driving. Right blinker works fine, both front amber blinkers work on run and blink. So, yesterday's project was to quickly clean socket for the outboard 3057 (closer to driver edge of car) as that bulb did not light for general running (i.e. dark) , whilst IN board 3057 closer to license plate was lit. Confused: Bulb looked fine, cleaned connector, mild scrape of contacts with small file to get corrosion away. Bulb contacts clean on bulb. Same problem. Darn!!! Ok, check INboard bulb and to surprise it was very corroded as was connector. Cleaned both, reinstalled. Same problem. Ok, replaced both 3057s with brand new from auto parts store. Same problem. Ugh ! Checked wires on connectors, no cracks or damage. (And it's worked for a few months, then not.) When I turn stalk to Left, the OUTboard bulb lights bright and stays frozen. But, seems like the INboard bulb gets dimmer or just no change. I see that working blinker on Pass side blinks both bulbs. (I was alone so couldn't see brake light action, but I could see reflection of brake light off shiny wall and seems ok.)

HOW are these two bulbs wired for working together to NOT blink on a bad bulb or connector? I'm going to reclean with WD40 cont cleaner, but Man, so frustrating that new bulbs won't fix. THANKS!! Any help appreciated; this been driving me nuts for years. Good place to buy new connectors?