temp gauge not working

[mexlokote]

based on images

A - wire is not connected, i dnt know where should it go connected at,

B - wire is connected directly to the temp sending unit,

based on the diagram that is on my haynes repair manual they go both connected together somehow i do not know how, im not sure what the diagram is telling me,

gauge is not working it stays in cold, but i do have some overheating issues but i want to fix the gauge first, the A - wire which is disconnected i tried grounding it and it does send the gauge all the way to hot,, anybody has any idea where can this A wire go connected at,

i have new choke,sending unit and thermostat and already checked the fuses which are fine,