4.3GL Fuel Pump Problem

[Sunken Ship]

Having some problems with a fuel pump (bench tested good) that I was hoping I could run by some of you. The boat is a 2000 Larson and the PO chopped the fuel pump wires and rigged up something to make it work. I would prefer to correct this.

I have studied the 4.3GL-A wiring schematics, which are the closest I could find of my actual motor.

Trying to figure out how the fuel pump is actually driven and why the PO rigged it. Is this correct:
1. Terminal 30 on the fuel pump relay is 12v switched in run and crank mode; and
2. Terminal 85 (relay) is supplied with 12v during crank via Y/R wire and is then driven by L2 (alternator) when the alternator spins and provides 12v to 85 in run position?

Thanks for any help.

 

[Maclin]

May be a diode in there somewhere. I won't be much help, have to see it and try things when they have been messed with like that. By way of previous owner reasoning, many owners of the 4.3 electric fuel pump engines, Merc and Volvo alike, added a momentary switch to hit the fuel pump with just the key on to fill the carb bowl and allow for shorter cranking times. On Mercs it is a fairly simple jump type connection right at the oil pressure switch . As you can tell from yours, it is not quite as obvious what to do without buggering it up some.

 

[tlombard]

I have a 2004 Caravelle with what should be the same motor. I can't get back to the boat until Friday and won't be back to a computer until Tuesday (we're camping Friday through Monday with no reliable cell service) but if I can remember I'll take some pictures and poke around with a test light to see if I can't map it out for you. I just set a reminder with a note on my phone on my phone to go off Saturday and Sunday morning while I'm down at the lake.

 

[Sunken Ship]

Thank both for the responses and willingness to help. I got it going today. I think the PO put the wrong wire on the "exciter" terminal of the alternator, according to the local alternator shop. I took pictures during disassembly of the engine and put everything back as it was. On to the next problem....gauges.