Help!! Lost power to fuel pump.

[Steveboyd]

Help!! I have a 99' Larson with 305 and Volvo penta outdrive. Love the boat. We went our yesterday and at end of day we started hone and motor died. After paddleing back to beach. I popped cover off and started looking. Engine would crank just fine bur would not fire. So I knew it was either spark or fuel. I cracked presure side line of fuel pump and turn on key and no fuel and no noise of pump running. Directly above fuel pump is a 50amp breaker. There's power to both sides of breaker. Next inline there is a relay I pulled relay and there is only power to one leg of relay. I was able to make a jumper wire from power leg of relay plug to leg and powered pump to get home. Could it just be the relay?Or is there some sort of fuel pressure switch that's not telling relay to open therefore not powering fuel pump?Any idea??Thanks so much!!Steve

 

[mcw]

Start with the basics.

If you had a loud buzzing fuel pump when running chances are its knackerd, a common sign of a failing fuel pump is it gets loud.

The fuel pump is worked of the purple ignition wire in the dash, if all is working on the dash board side meaning gauges, turning the ignition will energize the purple wire on the gauges and back down to your alternator and fuel pump relay.

with ignition key turned to position 1 meter the connector that runs to the terminal connector for the fuel pump will be a yellow wire, yellow + black is the common, you should have 12v approx., if no 12v, then meter the relay wires for the fuel pump relay which are red and common black, if 12v is present then its the fuel pump/

See how you go with this first

mark

 

[WoodieMan]

If there is 12V at the pump with key on, then relay is good and pump is bad. If no 12V at pump, work back from there. Some apps have 2 relays; one for pump and one for start (depends on app) that are the same relay and are interchangeable. Also check oil pressure switch. I suspect the pump circuit gets powered through there (safety feature).