Audible Alarm

[jrd_mon]

Trying to get the boat ready for summer and I'm getting a loud beeping from the engine compartment. I'm assuming it's due to low oil pressure. When I turn the key to ON the oil pressure gauge shows no oil pressure. When/how is the oil pressure supposed to go up? I have a Volvo penta v6 4.3GLPEFS serial # 4012047878. I just changed the oil last night and put on a new oil filter thinking that would make the beeping go away but it didn't. I'm also not getting power to my fuel pump when I turn the key to start. There's power to the relay and it's a new relay that is working when I energize it. And the fuel pump works when I jump the relay. Is it possible that when the beeping is going it prevents the relay from being energized and sending power to the fuel pump? Thanks in advance for the help!

 

[Don S]

Re: Audible Alarm

Trying to get the boat ready for summer and I'm getting a loud beeping from the engine compartment. I'm assuming it's due to low oil pressure. When I turn the key to ON the oil pressure gauge shows no oil pressure. When/how is the oil pressure supposed to go up?

You have to start the engine to get oil pressure.

 

[jrd_mon]

Re: Audible Alarm

Yeah I couldn't remember if that was the case or not from last year (my first year with a boat.) When I turn the key to START the boat won't start because the fuel pump isn't pumping fuel because the relay isn't getting energized. I'm wondering if the alarm going off could have anything to do with the fuel pump relay not getting energized. What conditions can cause that alarm to sound?

 

[Don S]

Re: Audible Alarm

How do you know the relay isn't getting energized. The pump doesn't start running until you crank the engine over.

Do you pump the throttle a couple times before cranking the engine? You may need to give it some throttle as well.

 

[jrd_mon]

Re: Audible Alarm

Yes I've pumped the throttle and given it throttle while trying to crank. I've also disconnected the fuel pump from the wiring and there's no power getting through the relay when the key is in START. But the relay does energize when I test it by itself. I'm really curious as to why the alarm is going off. Could it be related to the relay issue?

 

[skydiveD30571]

Re: Audible Alarm

The alarm is for low oil pressure. With no engine running, you have no oil pressure. That's all it is, it has nothing to do with your fuel pump or relays. Any boat with an oil pressure alarm will sound when the key is turned on and the engine is off.

 

[jrd_mon]

Re: Audible Alarm

Thanks for the info about the oil pressure. I'm sure this alarm wasn't going off last summer though so perhaps it's not related to oil pressure. It's very loud. It may just be time to take the boat into a professional.

 

[jrd_mon]

Re: Audible Alarm

Update. Been doing some testing tonight with the voltmeter. I know my starter relay is working (at least it clicks when energized.) I know my diode between the starter relay and the fuel pump relay is working and that the yellow/red wire between the starter relay and the fp relay is continuous. I also know from last night that I've got power at my fp relay from the starter.

 

[jrd_mon]

Re: Audible Alarm

How many volts should be getting past the diode to the fuel pump relay in order to excite the relay? I'm getting less than 1 volt with the key in START. I am getting plenty of volts to the starter solenoid though so the engine tries to start but it's starved for fuel.

 

[skydiveD30571]

Re: Audible Alarm

The diode shouldn't restrict voltage amount. It is simply a one-way protection device. It keeps electrical current from traveling the opposite way on that wire. Using your voltmeter, measure the voltage in front of and behind the diode and see what the difference is.

 

[jrd_mon]

Re: Audible Alarm

I'm having a hard time finding the diode. It must be under a bunch of black tape. The only thing between the starter relay and the fuel pump relay is a strand of wires wrapped in black electric tape. I guess I'll need to unwrap it all. Could a bad connection be the reason for the low voltage?

 

[skydiveD30571]

Re: Audible Alarm

Take a look at this page of your service manual. It is the fuel pump wiring diagram. Looks like there are a couple diodes and a circuit breaker. It should help you follow what's going on.

 

[jrd_mon]

Re: Audible Alarm

Thanks for the link!!

 

[jrd_mon]

Re: Audible Alarm

Made a break through tonight. Found out the wiring has been changed at some point so the wiring diagram in the service manual is no longer correct. There is a wire going directly from the ignition switch (start position) to the starter relay. The problem now is I don't have a clue what has been sending power to the fuel pump relay when the ignition switch was turned to start?? What ever it is, I'm guessing it's associated with the annoying alarm going off now when I try to start the boat. That wasn't happening last year. Is there some other item on the boat that gets power sent to it when the key is in Start that might also cause the alarm to go off? I'm planning on getting a new diode and tapping into this after market wire that's feeding the starter relay and using it to power the fuel pump relay. What size diode should I get?

 

[skydiveD30571]

Re: Audible Alarm

If it was my boat I'd disconnect that extra wire that a previous owner installed. And then trace the yellow/red wire from the ignition switch, to the control arm, then towards the engine compartment and see where it leads. Whoever installed that other wire was trying to bypass this wire for some reason. Also, it goes through the control arm so that you cannot start the boat in gear. You don't want that bypassed.

 

[jrd_mon]

Re: Audible Alarm

Thanks for the input. You're correct that it does bypass the control arm so we can actually start the boat in gear. I'm going to try and put it back the way it should be tonight. Thanks for your help!

 

[Don S]

Re: Audible Alarm

Made a break through tonight. Found out the wiring has been changed at some point so the wiring diagram in the service manual is no longer correct. There is a wire going directly from the ignition switch (start position) to the starter relay. The problem now is I don't have a clue what has been sending power to the fuel pump relay when the ignition switch was turned to start?? What ever it is, I'm guessing it's associated with the annoying alarm going off now when I try to start the boat. That wasn't happening last year. Is there some other item on the boat that gets power sent to it when the key is in Start that might also cause the alarm to go off? I'm planning on getting a new diode and tapping into this after market wire that's feeding the starter relay and using it to power the fuel pump relay. What size diode should I get?

If it's going to the relay, the only thing bypassed is the neutral safety switch in the control. The start relay powers the fuel pump relay, so that is why you was getting power to the fuel pump.

Here is a better wiring diagram of your engine wiring.

View attachment Wiring Diagrams 4.3GL.pdf