Join the C34 Association Today!
[C34 Home] [C34Tech Notes] [C34 Tech Wiki] [Join!]
Please login or register.
Advanced search  

News:

Pages: [1]   Go Down

Author Topic: Fuel gauge sender question  (Read 217 times)

0 Members and 1 Guest are viewing this topic.

Tallship2

  • Forum - Seaman Apprentice
  • *
  • Karma: 0
  • Posts: 2
  • Crusader Rabbit 1987 C-34Hull #788
    • View Profile
Fuel gauge sender question
« on: November 23, 2019, 05:09:21 PM »

I have a problem with my fuel gauge on my 1987 34. The gauge works because when I short across the sender post and the ground post the gauge reads over full. So I finally got in to look at the tank and here's what I found. The wire from the center pole on the fuel tank sender goes to the hot lead on the fuel pump. The a second wire goes from one of the mounting screws to a ground bracket on the tank and then on to the sender pole on the fuel gauge. Somehow this doesn't seem correct. Is this the way the wiring is supposed to go?
Logged

KWKloeber

  • Forum - Master Chief Petty Officer of the Navy
  • ********
  • Karma: 32
  • Posts: 3428
  • "Positive Impact" 1984 C-30 #3573 trbsfk M-25
    • View Profile
Re: Fuel gauge sender question
« Reply #1 on: November 23, 2019, 08:45:39 PM »

No that is complete back-a$$wards.  No hot wire goes to the sender. Only a pink signal wire from the gauge.  And the body of the sender grounded.

[EDIT]
PS the gauge should pin low with the pink wire removed from the sender.
The pink wire is connected to the S terminal of the gauge and the gauge is sensing the impedance of the circuit to ground, thru the variable resistance of the level sender.
Hot juice goes to only the gauge.
The sender may be grounded directly to a 12v negative (the most reliable way) but it could also be grounded to the tank ( the tank should also be bonded to the negative buss (green 14 ga wire.))
Make sure there is a proper gauge ground - the OEM harness negative to the exhaust manifold stud is TERRIBLE and should be redone correctly.  As well the battery negative cable should be on a starter bolt, not on the bell housing.
« Last Edit: November 24, 2019, 07:52:34 AM by KWKloeber »
Logged
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Tallship2

  • Forum - Seaman Apprentice
  • *
  • Karma: 0
  • Posts: 2
  • Crusader Rabbit 1987 C-34Hull #788
    • View Profile
Re: Fuel gauge sender question
« Reply #2 on: November 24, 2019, 06:02:54 PM »

Thanks, that's what I thought. The wiring is obviously not the original, as the wire going to the fuel pump is blue, and the wire going to the gauge is black. This is in line with the wind gauge which reads 180 degrees off and was obviously put on backwards.
Logged

DaveBMusik

  • Forum - Petty Officer 1st Class
  • *****
  • Karma: 2
  • Posts: 232
    • View Profile
Re: Fuel gauge sender question
« Reply #3 on: November 25, 2019, 08:17:08 AM »

Ahhh, PO can mean previous owner. It can also mean pissed off...
Logged
Dave Burgess
Water Music
1986 C34 Hull #206, Fin Keel
Yanmar 3YM30
Noank, CT

KWKloeber

  • Forum - Master Chief Petty Officer of the Navy
  • ********
  • Karma: 32
  • Posts: 3428
  • "Positive Impact" 1984 C-30 #3573 trbsfk M-25
    • View Profile
Re: Fuel gauge sender question
« Reply #4 on: November 26, 2019, 01:47:39 PM »


Thanks, that's what I thought. The wiring is obviously not the original, as the wire going to the fuel pump is blue, and the wire going to the gauge is black. This is in line with the wind gauge which reads 180 degrees off and was obviously put on backwards.


You're obviously headed the wrong direction, turn the pointy end around.

A light blue wire is ABYC standard for oil pressure, and dark blue is lighting circuits.
And black is **always** a DCv negative (unless it's an ACv hot) :shock: Outch.
Logged
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain
Pages: [1]   Go Up