I have a 1969 Fj40 and recently replace the fuel sender with a new OEM unit for the same year. When I turned the key, the gauge slowly went up and then stopped at the E. I have about 1/2-3/4 tank of fuel in the tank. Why did my gauge only register to the E? When the key is off, I can't even see the needle. Could the needle stop be broken? Is this easy to fix? Any help would be appreciated.