[OKCSuburban]

I use to have a friend who traced down these types of problems. He has not been seen for several years...
What is the cheapest thing you could do?
Maybe check the socket, and start from there following the solder lines.
Time, lots of time can be invested in a project like that and the fix could be as simple as a crack in a solder line or something like that. I am getting old and blind so I have one of those visors with high power glasses attached just to pull splinters. Something like that might be helpful.
Do you really need a turn signal light?
Best of Luck to ya.