i have an eletric sender for a blox oil pressure gauge with trhe sensor itself grounded to the head and the sending wire running straight from a toggle switch, it gets power the light comes on and i see the needle barely move when its switched on. the problem is i havent started my motor i was trying to get pressure before i tried but i crank and crank but cant build up anything, is thhis because its not running or is something else going on?

 

why would you wire up a sensor to a toggle switch?