Fuel Pump wiring

S

Steve the plumber

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My buddy has a volvo outdrive with the 5.0 engine(GM). I don't know all the numbers cause its not my boat.
He was having trouble and I tracked it down to the fuel pump not running. I little vertical mounted centrifugal unit.
It has a 5 pole relay. I hot wired the pump and it works fine. So I tested to see if the wires going into the relay had power going to them. So he does the ignition switch while im on the meter and alas there is power going into the relay wire block. Bad relay right? I went with him to buy the relay and it was the right one. He went up over last weekend and it didn't work, he even bought another one.
WHats going on here?

Thanks
 
You might check the oil pressure switch. Fuel pump won't run when no oil pressure is present.
 
Except if it is the right pump and wired correctly the pump should prime the system... briefly... when the key is turned to the On position , possibly have an oil pressure switch bypass supply circuit in the Start position , or otherwise already have supplied enough fuel during prime to start and run for 2 seconds , long enough for the engine to build enough oil pressure for the oil pressure switch to allow the fuel pump to activate on demand.

Still...., check the OP switch as suggested .

Normally there is also a fuel pump fuse , but I would think that would feed the realy , not the pump directly .
Check the connector plug or terminal connections between the pump and relay . I once had a barely bent connector pin causing intermittent fuel pump shutdown, then finally a no-start condition. A serious Wiggle Test of engine harness wires with key ON , engine off(obviously) revealed the culprit vicinity when the pump started up. Always worth a try.
 
posting the ign and the type of carb or fuel injection would be helpfull too.
 
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