Yeah, I haven't had recurring problems with Classic. I even use their part numbers in my How-To articles. But I am flabbergasted at how a fuel gauge can point straight down from its mounted position and be okay.. so to your point..
go back to your bench.. put the power supply on the power terminal of the gauge and the negative to that smooth point under the gauge that needs to be grounded. Reading should be FULL. If it reads full the gauge is good. Install it and don't look back. Dads has a good method there. Good luck!
