Volvo 4.3 GLA Fuel Pump Problem/parts

My fuel pump (on a Volvo 4.3 GL) quit working yesterday. I checked the relay on a workbench. It works. When I energize the coil with 12 VDC the Normally open contacts close.

I tried jumpering the normally open contacts on the relay and the fuel pump ran. I could then start and run the engine.

I read somewhere on here that the fuel pump runs through the alternator. When I did run the engine, the voltmeter on the dash staid at about 12V. Normally I have seen it at about 14V when the engine is running and after turning off the blower.

After I got back home, I found an electical drawing for the 4.3GL online. I noticed two diodes in the electrical drawing. Are they there because it is a DC coil?

I hate mechanical stuff. Not my forte. I did some on cars many years ago when I was young and poor. Have been fortunate enough not to have to deal with auto repairs myself for thirty years or so. I just buy new cars every few years. New boats cost too much and mine seem to have problems mostly around holiday weekends.

I would like to buy some spare parts for this engine but the only parts catalog I can find on line costs 28 bucks from Volvo. Anyone know where I can download one?

I hope the alternator solves the problem.

Thanks,

eezie

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

If you look up just above your post, you will see a link to Volvo Penta Parts. That is the OEM parts breakdown with up to the minute part numbers. It IS the Volvo OEM lookup. And it's free.

I also have links the the Volvo OEM service manuals located HERE.

The fuel pump does not "Run" through the alternator, and if you battery is staying charged it's probably not a bad alternator.
Fuel pumps on marine engines do not run when just turning on the ignition. The pump only runs when the key is in the start position, as the FP relay is energised by the ignition switch when cranking the engine (start position). Once the engine is running, the alternator sends power through a diode to the fuel pump relay to keep it energized. If that diode is blown, then power will not get to the relay. But if you also can't start the engine until you manually run the fuel pump, then you have either a problem with the relay itself or the wiring to the relay.

If you put a jumper across the 30 and 87 terminals of the relay socket and the pump runs, you know the pump is ok.

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

Thanks for the links Don. I did jumper 30 and 87 and the pump did run.

If the alternator is good then I guess it's the wiring or diodes.

Will order new diodes just in case.

The wiring is all taped up so not sure where those diodes are located in the harness.

eezie

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

Can't find the diodes in the parts list.

Are they generic? Available at any parts store?

eezie

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

Why don't you download the wiring diagrams and test them before ordering. You don't have to open up the harness to test the diode.

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

The boat is 50 miles away. Auto parts store and internet are available.

Also, I am not sure where, in the harness the diodes are. Would rather not tear it apart unless I need to.

Thanks,

eezie

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

Just because the alternator is charging the battery does not mean it is outputting voltage to the fuel pump relay. That output off of the alternator is separate from the charging output. With the engine running by bypassing the relay, check the voltage at the L1 terminal of the alternator. That is the terminal that feeds the fuel pump relay through the diode.

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

<Just because the alternator is charging the battery does not mean it is outputting voltage to the fuel pump relay. That output off of the alternator is separate from the charging output. With the engine running by bypassing the relay, check the voltage at the L1 terminal of the alternator. That is the terminal that feeds the fuel pump relay through the diode. >

I think I did that but will again. I also checked for continuity with an ohmmeter between the L1 terminal and terminal 85 on the relay. However, I did not know there was a diode in the circuit at the time. Not sure but I think with a good diode, I should read a short or a few ohms in one direction and open with opposite polarity on the VOM.

If the L1 terminal is not putting out voltage to the diode, I assume I am still in need of a new alternator?

Thanks,

eezie

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

Still would like to know where those diodes are located and where to buy them. A part number might help with an internet search.

I figure they would be fairly cheap and a good thing to have with me when I go back to the boat with the alternator.

eezie

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

Dpending on the multimeter, they may not have a high enough voltage to turn on the diode so it may read high impedance in both directions.

Instead, with the relay bypassed and with the engine running, measure the voltage at the coil terminal of the relay so that you are measuring after the diode.

I really really really doubt the diode is bad.

For another test, you can remove the wire from the alternator and jump that to 12V and see if the pump turns on. You can at least hear the relay click on that way.

Re: Volvo 4.3 GLA Fuel Pump Problem/parts

Well, a new alternator solved the problem. Now I have a new problem. The damned engine won't shut off when I turn off the switch. Sheesh.

Going to start a new thread for that one.

eezie