'Wiring for 2000 Volvo 4.3 on a 2001 larson

[$20boat]

I have the site with the shop manual for the gray motors, but my wiring to the 2 relays and fuel pump don't match the manual (7743244 for the fuel system or the system wiring 7743245).

Any suggestions/help on how to get the correct wiring diagram? My engine is a 4.3GLPEFS

THANKS!

 

[Don S]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

What's different?

 

[$20boat]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

THE 1st relay plug has a gray wire, a red wire (from starter), a yellow wire and a yellow/red wire. The wiring diagram shows 2 Y/R, one black ground wire and a red (hot).

 

[Don S]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

Gray is for tachometer, sounds to me like someone did some wiring repairs without the proper color coding. Follow the gray wire and see where it goes to and from. What terminal on the relay is it on. 85, 86, 87, 30 ???? And what do you mean by 1st relay. Is it the start relay, or fuel pump relay?

 

[$20boat]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

I have to watch myself, i'm red/green color blind. I think the gray is on 86, but i will go check.

I have not been able to locate the 40 amp fuse, is it usually around the throttle housing?

 

[$20boat]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

the gray wire is on 85

 

[$20boat]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

i won the boat in a raffle ($20boat), but the wiring does not look like its been monkeyed with. the boat has a little more than 100 hrs on it.

the problem is that the fuel pump is not working. there is power to the 2nd relay adjacent to the pump, but no power is applied to the pump.

According to the wiring diagram, there is an orange wire (changed from a y/r from the 1st relay) and a green wire (from the alternator) that should trip the relay when starting the motor.

I have tested the connections for power and continuity, but i need to redo this and write it all down.... That way i can get you info to help and sort things out in my own mind. it'll have to be tomorrow since it's now dark here.

 

[Don S]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

The orange wire "Trips" the relay when starting. More precicely, when you turn the key switch to the start position, you get power to the start relay to engage the start solenoid, and at the same time you get power to the 85 teriminal on the fuel pump relay through the orange wire to engage the fuel pump relay. Once you let off the ignition switch to the run position, the fuel pump and starter no longer get power from the key switch. The fuel pump then gets power from the alternator throught the green wire. Note. there are 2 diodes in the fuel pump system. One on the green wire, one on the orange.

 

[$20boat]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

Roger on the current flow to the relays. i believe that perhaps the diode is bad, but i don't recall what the voltage is on the 1st relay post 85. i know there is no power to the 2nd relay 85. i took resistant reading on the y/r relay 1 to relay 2 and it was high if i recall correctly, not what you would expect if the diode is good.

is there any easy way to locate the diode? i did reverse the meter leads to check the path both ways, didn't write it down though.

 

[$20boat]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

Don, thanks again for your help. This morning's test results are the following:

1st relay
Post Situation Result
30 key off 12V
85 Key off or starter on 0V
86 off 0V
86 starter on 10.5V ( should be 12V i think) This is Y/R

Relay 2
85 off 0
85 starter on 7-8 expected closer to 12V
85 igniton on 1.6V
30 off 12
87 off 0V
87 starter on 0V

 

[Don S]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

1st relay and 2nd relay tells me nothing. I Haven't seen an EF 4.3 in a while, and I just don't remember how they are layed out or which ones you are referring to. So do this. Refer to them as START relay, and FUEL PUMP relay. Then there won't be any questons. Also, since I have no idea HOW you checked the relays, the readings don't really mean much either.

Now, as far as testing the relays (They both test the same)
Remove the relays, NOTE: since both relays are removed, the engine will not crank and the fuel pump will not run.
Hook up your volt meter to the relay sockets, test from 85 (red lead) to 86 (black lead). With the key off, you should have 0 volts.
With the key in the crank/start position, you should see battery voltage.
That is the test to see if your wiring is doing what it should be.

On the 30 terminal of the socket with your red test lead and your black lead to ground, you should see battery voltage. Doesn't matter where the switch is. Off, on or start, you WILL or should have battery voltage.

87, will only get power if the relay works. All the relay is doing is connecting 30 and 87 to make the engine crank or the fuel pump to run.

On the fuel pump relay socket, if you put a jumper wire between the 30 and 87 terminals, the fuel pump should run. Even if the ignition switch is turned OFF.

 

[$20boat]

Re: 'Wiring for 2000 Volvo 4.3 on a 2001 larson

Don, excellent point! Relay 1 is the main relay or starter circuit control. Relay 2 is the fuel pump relay.

i checked the relays using the instructions in the shop manual you posted on the share site for a 4.3GLPEFS motor.

to cut to the chase, i have performed most of what you recommended today. What i found was that the yellow/red wire (goes from starter relay to fuel pump relay) that activates the fuel pump relay to allow power to the fuel pump has a 4 volt drop in the line (reads 8V instead of 12). This line also contains a diode, which i suspect is bad. The hot line to the fuel pump relay reads 12V, but the relay is not triggered. I assume this is because 8V is not enough to trigger the relay.

Tomorrow i plan to take readings in both directions across the diode. My understanding is that it shoudl be infinite in one direction and zero in the other. I don't know if this is spec for this diode; are there any other parameters i can measure? Also, i live in a small town and the local auto parts store told me they don't carry diodes. Is there a specification i need to have in order to get the correct diode if one is needed?

Thanks for your excellent inputs!