Hi Kai ,

with thanks for the really helpful reply ,i have to say when i first opened the Fuel level meter i pretend in my mind that if this contactor for any reason make a spark ,the fuel tank will be exploded .
then when i looked at the original Fuel Gauge i saw a winding that has ~10 Ohms (if i remember correct) seried along the Fuel Level Meter winding and it is 30 years that it doesn't exploded !. still i have fear to burned in the car and i am sure lowering the current that flows thought the gauge will degrade the chance of making sparks . but i don't know ,if for example i use a 10k ohm resistor along the gauge and lower the maximum current to about 1.2 mA the chance of making a spark will be Zero .
and considering the Summer ,wheather temp goes up to 38 'C ,and the Feul will be Completely ready to explode .
So any Help on this would save an 8052 hobbyist live !.

Farshid J.H.