both methods will work scraping off the rust and the soldering one in my case I Hope this helps, I had the same exact problem on my 540i E39 on my passenger side tail light every light would work but one, my turn signal would not blink , I tried switching sockets from my working tail light to the non working one and no cigar, A Friend of mine tested the board on the tail light with some alligator connectors and a small battery all lights worked so that told me that she board is good ,I noticed the same corrosion on some prongs what I did , I wrapped a butter knife with a piece of paper towel and sprayed PB Blaster inside the tail light connector I let it soak for about 2 mins all You do is rub the connectors with the knife and towel until it looks clean kinda silver looking again , just repeat as needed Pb blaster brakes off rust that did the trick for me .
You have to understand WHY the original plugs corrode....then you can fix the issue. Soldered straight is tacky and cutting corners. When you cut corners you know have 2 corners...that applies with alot in life as well
both methods will work scraping off the rust and the soldering one in my case I Hope this helps, I had the same exact problem on my 540i E39 on my passenger side tail light every light would work but one, my turn signal would not blink , I tried switching sockets from my working tail light to the non working one and no cigar, A Friend of mine tested the board on the tail light with some alligator connectors and a small battery all lights worked so that told me that she board is good ,I noticed the same corrosion on some prongs what I did , I wrapped a butter knife with a piece of paper towel and sprayed PB Blaster inside the tail light connector I let it soak for about 2 mins all You do is rub the connectors with the knife and towel until it looks clean kinda silver looking again , just repeat as needed Pb blaster brakes off rust that did the trick for me .
did almost the same for touring but with a knife. this saved me from paying 80 euros for a new taillight.
soldered wire safer than junk factory plug . solder New plugs for super tacky but correct upgrade and don't get rear ended
You have to understand WHY the original plugs corrode....then you can fix the issue. Soldered straight is tacky and cutting corners. When you cut corners you know have 2 corners...that applies with alot in life as well