Well, after fidling with my continuity tester, I found that even if there continuity across the small filmstrip located above the speedometer, current will not go thru. Wierd enough....
However, I used a Cat5 strand to make some sort of "bridge" between both screws. Speedo worked and alternator started to charge, but fuel and temp gauges didnt move at all.

I will recommend anyone performing some work on their aging clusters to clean thoroughly the contact surfaces for the conectors and adding some sort or protection ( I used a small dab of dielectric grease)I found those connectors covered in green junk (probably brass connectors) and this could cause erratic readings on your cluster.

Now, back to work on those temp and fuel gauges, any tips?