89 Mercedes 190E no power to fuel pump car been running fine about a week ago I park it came back out no start not getting gas. Had someone check out both pump both are good but not geting any power to them. Replace the relay and a box that look like a relay in back of the batt still the same then for a unknow reason it started to work got it home then it went back to no power. What doing this

 

Fuel pump relays are very common and fail due to high amperage draws from the pumps. Make sure that the solder connections at the connection for the relay are ok and the pins are not spread out and making intermittant/light contact. Other than that, it's difficult to tell without looking at it. check all the fuses though.

 

I am thinking ignition switch the pump stop then after trying anything I could try for 4 days it started again. now it stop again I did replace the relay. all the fuses look good. What one is for the pump ?