fuel gauge question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68_c10_on20s · 07-26-2003, 05:43 PM

i just installed a under bed tank and ran the wire up the gauge it worked fine for a few days then quit when i hook it up it reads emty when i unhook it it goes way past full,should i test the wire with an ohm meter or what else could it be my ground is good and it was workin but no more really sucks not knowing how much gas i have any advise?

Bill72BB · 07-26-2003, 06:21 PM

If I remember correctly that means there is a problem with the sending unit ,could just be a float filled with gas.

Good Luck.

lukecp · 07-26-2003, 06:26 PM

It is supposed to go way past full when it is unhooked. Either the float is full of gas as Bill suggested, or you have a bad sending unit. Testing the resistance wouldn't be a bad idea. I think the fuel guage works form 30-90 omhs, 30 being full and 90 being empty....so if you fill the tank and the wire reads 30 omhs, your float is proably full of gas. I'm not totaly sure on the omhs readings....anyone else know for sure?

Kman · 07-26-2003, 06:44 PM

go to your sender and ground the wire and have someone watch the gauge( with the key on) if it pegs your sender is bad, if no change go to the gauge and ground the terminal for sender if the gauge pegs its the wiring if no movement its the gauge, as long as you have 12 volts to gauge lol
Kman

68_c10_on20s · 07-26-2003, 07:59 PM

ok heres what i did i turned on the key gauge was on e then unhooked ground it pegged out,hooked back up and back to e must be the float then huh? how could it have got gas in it a pinhole or what?

tom hand · 07-26-2003, 08:44 PM

I don't remember who it was but someone on this board bought an underbed tank that had a bad float right out of the box

Longhorn Man · 07-26-2003, 10:43 PM

A pin hole, or more likely, a bad soldering job assembling the float.

07-26-2003, 05:43 PM	#1
68_c10_on20s Registered User Join Date: Aug 2002 Location: Waxahachie TX Posts: 773	fuel gauge question i just installed a under bed tank and ran the wire up the gauge it worked fine for a few days then quit when i hook it up it reads emty when i unhook it it goes way past full,should i test the wire with an ohm meter or what else could it be my ground is good and it was workin but no more really sucks not knowing how much gas i have any advise? __________________ 93 Fleet Budget Build http://s150.photobucket.com/albums/s...zted71/hoopty/

07-26-2003, 06:21 PM	#2
Bill72BB Thats the Hillbilly way Join Date: Jul 2001 Location: Torrance,Ca Posts: 5,980	If I remember correctly that means there is a problem with the sending unit ,could just be a float filled with gas. Good Luck. __________________ BILL Torrance Calif 90504 Member DUF Club Member Old Farts Club 72 3/4ton Custom Camper BB402/400 trans Dynomax Cerama-coat headers , Hei distributor ,Edelbrock 1411 air,ps,pb,leafsprings ,98 chevy 60/40 seat,S10 shoulder belts tilt,3.54 Dana 60 rear. 16" Eagle wheels with LT265/75 16 tires,Gaylord Lid,H4 headlights with 100W relay conversion. " If I knew I was going to live this long I would have taken better care of myself " Marriage changes passion...suddenly you're in bed with a relative. A GUY'S PRAYER.... Lord, I pray for a nympho with huge boobs who owns a liquor store and likes to fish and hunt and has a Harley .Amen ,

07-26-2003, 06:26 PM	#3
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	It is supposed to go way past full when it is unhooked. Either the float is full of gas as Bill suggested, or you have a bad sending unit. Testing the resistance wouldn't be a bad idea. I think the fuel guage works form 30-90 omhs, 30 being full and 90 being empty....so if you fill the tank and the wire reads 30 omhs, your float is proably full of gas. I'm not totaly sure on the omhs readings....anyone else know for sure? __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

07-26-2003, 06:44 PM	#4
Kman Registered User Join Date: Sep 2002 Location: Melbourne,Florida Posts: 174	go to your sender and ground the wire and have someone watch the gauge( with the key on) if it pegs your sender is bad, if no change go to the gauge and ground the terminal for sender if the gauge pegs its the wiring if no movement its the gauge, as long as you have 12 volts to gauge lol Kman __________________ New 89 chevy 1500 driver 72K20 rust bucket project stripped down to the frame engine rebuild started 71 Blazer - another procect

07-26-2003, 07:59 PM	#5
68_c10_on20s Registered User Join Date: Aug 2002 Location: Waxahachie TX Posts: 773	sender ok heres what i did i turned on the key gauge was on e then unhooked ground it pegged out,hooked back up and back to e must be the float then huh? how could it have got gas in it a pinhole or what? __________________ 93 Fleet Budget Build http://s150.photobucket.com/albums/s...zted71/hoopty/

07-26-2003, 08:44 PM	#6
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I don't remember who it was but someone on this board bought an underbed tank that had a bad float right out of the box __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

07-26-2003, 10:43 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	A pin hole, or more likely, a bad soldering job assembling the float.



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