Dandy. You should only see voltage to the fuel pump for about one second after turning on the ignition switch. That voltage will come back during engine rotation, (cranking or running). That is a safety feature to stop the pump from pumping raw fuel onto the ground if a fuel line gets ruptured in a crash.
If you're testing this with the fuel pump's electrical connector disconnected, use a test light instead of a digital voltmeter. Almost no current needs to flow in the circuit to get enough voltage for the meter to detect it and show 12 volts. That can be misleading. If you have a corroded splice, pitted relay contacts, or carbon-tracking across a break in the wire, the meter will show 12 volts but you won't get enough current through to run the pump motor. A test light requires substantial current to flow in the circuit for it to work, so it will give more accurate results.
Thursday, October 29th, 2015 AT 8:35 PM