Volvo penta 5.0gl fuel pump quitting ?

[Tim.D]

Was off shore the other day and the motor shut down. I checked and the fuel pump was not coming on when the key is in the on position. I bypassed the relay and was able to get the pump to work to get home.
I tested the relay at home with a volt meter and see it is getting 13.8volts, but the relay is not letting power through it. I bought a new relay but still the same problem. all fuses are good.

By chance can the alternator be causing this ?? Or any other ideas ???

Thanks Tim

 

[Don S]

Re: Volvo penta 5.0gl fuel pump quitting ?

The fuel pump will not run when the key is in the run position and the engine not running. When the key is turned to the start position, the fuel pump gets power from the start relay. Once running it gets power from the alternators green wire. You can check with the engine running to see if you have power at that terminal on the alternator. Power then goes through a diode to the relay to activate it.
The 30 terminal on the relay always has power on it. But terminal 85 is the one that activates the relay so it will put power to the pump.

 

[Tim.D]

Re: Volvo penta 5.0gl fuel pump quitting ?

Thank you , for your response. I will try that tomorrow. I was at wits end. How often might the diode go bad ??

Tim

 

[Don S]

Re: Volvo penta 5.0gl fuel pump quitting ?

I was at wits end. How often might the diode go bad ??

As often as any other piece of electrical equipment.
We're not going by averages here, it doesn't matter, your fuel pump doesn't work and you have to find out why.
Could be a broken wire, who knows, that's what troubleshooting is all about.

 

[mikeneal]

Re: Volvo penta 5.0gl fuel pump quitting ?

Like Don said, you have to start to gather more info to properly diagnose what the issue is. One other option is pump itself is going bad. I had one fail once and intermittently when you started boat , pump wouldn't start then would run carb dry and shut off. Like any other electric motor, sometimes the pump had difficulty from start up, once it is turning tends to keep turning. Took a bit of effort to figure out occasionally the pump would get voltage and not always start. I wired an indicator light to it in order to see if it was getting voltage and eventually found it always got voltage and sometimes motor didn't run. Replaced pump and all was happy. Not saying you should buy a pump, just throwing another thing out there to check.

 

[x3v614]

Re: Volvo penta 5.0gl fuel pump quitting ?

The fuel pump will not run when the key is in the run position and the engine not running. When the key is turned to the start position, the fuel pump gets power from the start relay. Once running it gets power from the alternators green wire. You can check with the engine running to see if you have power at that terminal on the alternator. Power then goes through a diode to the relay to activate it.
The 30 terminal on the relay always has power on it. But terminal 85 is the one that activates the relay so it will put power to the pump.

Dead On Don.. Same issue with a 1998/9 5.7 mercruiser.. Does a mercusier alternator also supply the fuel pump (and electric choke) after the starter solenoid has done it's job?? If so how is it wired so I can test it. Any diode and or relay external to the alternator.

Thx.. Mark

 

[Colliemcc]

Re: Volvo penta 5.0gl fuel pump quitting ?

think i'm kinda having problems in the same area..at first my fuel pump was not working but after fixing this prob now i have a new problem when i get the engine running the starter motor still has power...could this be because the diode has failed and is allowing power back on the yellow and red cable from the alteneter.. its a volvo penta 4.3 GL

 

[Colliemcc]

Re: Volvo penta 5.0gl fuel pump quitting ?

bump

 

[Don S]

Re: Volvo penta 5.0gl fuel pump quitting ?

Start a new thread with your question. You can link this thread as a reference, but when you ask a question at the end of an old thread of someone elses, few see or answer it.