Low voltage on oil pump circuit

[hharbor]

Got great help understanding circuit (thanks rodbolt). Actual cable to pump is fried. on SECOND pull of tank, ran 12 volts to pump and off we go. The wiring to the external tank is only showing 3.5 volts, as is almost the entire circuit. WHERE does the oil circuit pickup power on the "brown" wire. All the harness' are taped (no surprise). Some where I am losing voltage.
Both batteries at 12.5, at starter same, in bus in fuse box same.
The brown wire connector just before we leave the engine, "to broken wire, only shows low voltage.

So tracking a short. Large connector taped up just upstream of wiring to pump, next step is to untape and check for shorts there.

Would really like to know where the "brown" wire starts getting voltage and check it there. If it is low then I can go upstream from there. entire circuit is low.

thanks for any help, it is like 100+ in the shade, and I am getting a little dingy.

 

[rodbolt]

Re: Low voltage on oil pump circuit

the brown wire for the pump transfer is spliced into the key on yellow 12V about 6 inches aft of the engine harness 10 pin connector and can corrode.
untape it and have a look, also check the connector from the remote tank harness for corrosion.

 

[hharbor]

Re: Low voltage on oil pump circuit

THANKS, wish I would have checked for your reply on Sat right before I buttoned everything up. I was fried from the sun and had to get pump, batteries etc back in boat, I "think" that connector is what I had in mind to check next.

Ignorance... I am replying to check that I understand. "sorry"

The wiring to remote tank comes into engine compartment, goes through four pin connector... then gets taped. this leads to a large connector block a few inches aft of that connection (also taped). Is this the "the engine harness 10 pin connector" that you are describing? Feels like it.

Thanks for your patience. We just moved back in from hurricane IKE, and I am sure I have the manuals just can't find them. it is really tough to follow the wiring without the schematic, your descriptions are great. Just so much of it covered with electrical tape....

 

[rodbolt]

Re: Low voltage on oil pump circuit

engine 10 pin is the large round connector sitting in a holder,or at least it used to.
yes the oil transfer brown is spliced into the key on 12 yellow wire about 6inches aft(engine side) of that connector.