gas tank sending unit

Salty Sal

Petty Officer 2nd Class
Joined
Nov 14, 2003
Messages
143
During the early part of this season my fuel gauge was jumping<br />from E to Full. The culprit was a cracked ground tab located on<br />the top of the sending unit.(sending unit is 2 wired- ground and sender) I took the ground wire and clamped it to one of the metal gas inline tubes on the tank- which worked just fine as a ground. Last week I noticed the needle was bouncing around again- and now constantly registers E, even though I know I have at least 20 gallons of fuel in the tank.<br />Tried to troubleshoot. If I turn the ignition key to the ON postion without cranking the engine and touch the ground wire to any metal part of the tank, the needle will move just a hair clockwise (towards the full position)- so I gather there is power going to the gauge.<br />Took the sending wire off, and cleaned up the connection-(though if I look into the neck of the connector, I see some <br />copper oxidation- but I think their still should be pretty good contact) Does this sound like the float is hung up. Wires at the battery terminals seem to be OK. Since I'm dealing with GAS, I want to make sure I'm safeguarding myself. Is there any type of voltage going to the sending unit that I need to be concerned with? What is the proper way to work on this problem- do I need to disconnect all power from the battery?<br />Another thing that may be a clue- I also noticed my tach was jumping around-so I removed the harness that connects<br />from to the the throttle box and put some dielectric grease.<br />Seems far more steady, but if I tap it, the tach needle will move <br />a bit and then stabllize.<br />Any suggestions how and what to troubleshoot? Thanks for your suggestions.
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: gas tank sending unit

If you touch the sender wire to ground and get a full reading the you have a dirty connection or a bad sender the ground wire really should go under one of the sender screws to get a direct connection to the sender not the tank
 

Salty Sal

Petty Officer 2nd Class
Joined
Nov 14, 2003
Messages
143
Re: gas tank sending unit

Hello Laddies-<br /><br />OK. will place under one of the five screws of the top of the sender. I gather these 2 wires- sender and ground do not have <br />a current. Please confirm. Thanks for your time.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: gas tank sending unit

Salty seems like you need to get yourself a volt/ohm meter. We sure can't tell if you got juice flowin from here.
 
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