More Gas Tank questions!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

orange72350 · 03-30-2003, 02:21 AM

Here we go. My gas gauge was reading all the way empty, so i had a service shop in town look it over when the truck went for inspection. The tech said i needed a new sending unit, so i ordered one. It got here, i installled it, and low and behold, it still didnt work. Instead of working through the whole spread, the gauge only registers when the arm is between empty and one quarter. I can fill the tank right up, and the quage stays at 1/4 tank. The qauge functions like it should, but the full mark is at 1/4, and empty is way down at the botttom. I have been told that there is a resistor in the gauge that may be shot, but i dunnno. BTW, how big is the tank in my 72 c-10. Im thinking probably about 80 litres, but i got no idea. its sorta nice when figuring out how much gas is left!!!! Thanx in advance for any help i get.

Bill72BB · 03-30-2003, 03:57 AM

If you put a meter across the sending unit it should read 90 to 0 ohm's as you move the float.
Most likely the float is sticking or has a pin hole and has partially filled with gas.
Pull the brown wire off the sending unit the gauge should go above full .if this is OK .
Pull the sending unit reattach the brown wire and ground the sending unit then move the float up and down watch the gauge and see if it goes from E to F. If this is OK the sending unit is OK ,make sure the float isn't full of gas or getting stuck when you install it in the tank.

Good Luck

LudwigTheMad · 04-01-2003, 01:49 AM

knew sombody that had the same problem...untill he rotated the sending unit 90 degree's....so the float was moving into the larger side of the tank, insted of stopping about 1/4 way up by the wall of the tank......

03-30-2003, 02:21 AM	#1
orange72350 Registered User Join Date: Jan 2003 Location: Cold, Snowy High Level, Alberta Canada Eh Posts: 394	More Gas Tank questions!! Here we go. My gas gauge was reading all the way empty, so i had a service shop in town look it over when the truck went for inspection. The tech said i needed a new sending unit, so i ordered one. It got here, i installled it, and low and behold, it still didnt work. Instead of working through the whole spread, the gauge only registers when the arm is between empty and one quarter. I can fill the tank right up, and the quage stays at 1/4 tank. The qauge functions like it should, but the full mark is at 1/4, and empty is way down at the botttom. I have been told that there is a resistor in the gauge that may be shot, but i dunnno. BTW, how big is the tank in my 72 c-10. Im thinking probably about 80 litres, but i got no idea. its sorta nice when figuring out how much gas is left!!!! Thanx in advance for any help i get. __________________ 2003 yamaha raptor. Stock, but it still hauls!!!! 2000 skiddo mxz 700. Camoplast 1.5 inch track, jaws twin pipes, b+b can, custom built and weighted clutch, wiseco piston, high comp heads. its very fast. wow. 72 c-10 longbox. Bright Orange. Brand new 350, rv cam, performer intake, qjet, headers, 2 1/2 inch exhaust into hooker areo chamber mufflers. Body work coming soon. "dont let yer mind wander, its to little to go places by itself." "Forget the herse, cause i'll never die"-ACDC Back In Black "If It's To Loud, Yer Just Too Old" "I Love Anything Fast Enough To Do Something Stupid In" "Instant idiot, just add beer!!""

03-30-2003, 03:57 AM	#2
Bill72BB Thats the Hillbilly way Join Date: Jul 2001 Location: Torrance,Ca Posts: 5,980	If you put a meter across the sending unit it should read 90 to 0 ohm's as you move the float. Most likely the float is sticking or has a pin hole and has partially filled with gas. Pull the brown wire off the sending unit the gauge should go above full .if this is OK . Pull the sending unit reattach the brown wire and ground the sending unit then move the float up and down watch the gauge and see if it goes from E to F. If this is OK the sending unit is OK ,make sure the float isn't full of gas or getting stuck when you install it in the tank. 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 ,

04-01-2003, 01:49 AM	#3
LudwigTheMad Registered User Join Date: May 2000 Location: Ramona, CA Posts: 2,033	knew sombody that had the same problem...untill he rotated the sending unit 90 degree's....so the float was moving into the larger side of the tank, insted of stopping about 1/4 way up by the wall of the tank...... __________________ That's right, I'm back in the game again. No it's not pink..... 1972 Blue and White Suburban.



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