Can anyone tell me what the symptoms are when you have a bad fuel pump relay? As I mentioned in another post, my Blazer will hardly start after sitting for 10 hours (like overnight). Once it does finally start it runs well. I learned that when you turn the key (but not all the way to crank the engine) the electric fuel pump is supposed to turn on for a couple seconds to inject the fuel needed to start the engine.I don'thear the whirl of the fuel pump (in the gas tank) for the 2 seconds (so the pump is not turning on for the2 seconds that it is supposed to). Bottomline, what does the relay do and what are the symptoms when the relay goes bad?

Mo

 

you'll have to unplug the connector near your license plate light-there may be two connectors and take a multi meter or a 12 v test light and unplug the connector and see if you have 12v(or bright 12v test light) for the 2 seconds at key on-one of the other wires is the gas tank gauge which I believe is 6 volts(or half your normal test light brightness). If you have 12 volts for two seconds at key on your issue is to the rear, in other words pump or sending unit. I have a a couple (rare but possible) of Blazers with sender issues but this test should direct you somewhere and if it does this every day-you should be able to duplicate it. JP