fuel gauge and/or sending unit troubles - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevyfan420 · 02-10-2004, 03:01 PM

a couple days ago i switched my 79 back to gas from propane. i hooked the single wire for my gauge up to the wire coming from the sending unit and i bolted the ground wire from the sending unit to the frame. i poured a 5 gallon can in, started it up and my gauge read 1/4 tank. I thought ok, alright it works. later that day i put $25 in and my gauge never moved at all. the truck sat for a day. the next time i got in the gauge read 1/2 tank. i drove a bit and found a cheap station so i topped my tank up and it still reads 1/2 tank. later that day it reads a little under 1/2. does anyone have any ideas why its acting so screwy? does this sound like its my gauge or my sending unit? any help is greatly appreciated.

ps: anyone near Ontario want to buy a complete propane setup? tank to carb, it fits on a regular 4brl spread-bore intake.

Prerunner1982 · 02-10-2004, 03:05 PM

at the moment 3/8ths of a tank on the guage is a full tank. i have also had it 1/4 tank pass full as a full tank. check your grounds...then check float for corrosion where it would be making bad contact.

79BIG10 · 02-10-2004, 03:43 PM

Also your float may be stuck a bit. If you've not used it in awhile since you've ran propane then it might be stuck. If you have a 2nd tank fill it up as well and see if it works. If not then you know it the gauge. If it does then you know it's the tank wiring or sending unit.

chevyfan420 · 02-10-2004, 06:54 PM

it only has a single tank. i pulled the sending unit out of the tank to check it ,blow the lines out and to clean it. the float seemed to be free.
i think it has more to do with the gauge because it would register a reading while it was on propane. i checked and it was'nt hooked to my propane tank, so it was getting a signal (or whatever makes the gauge work) from somewhere.

79BIG10 · 02-10-2004, 09:41 PM

Strange for sure. Wonder what the gauge was reading then while on propane? I've got a copy of a schematic of the fuel wiring system if you need it.

chevyfan420 · 02-10-2004, 10:56 PM

yes, please send me a copy at:

chevyfan420@hotmail.com

79BIG10 · 02-11-2004, 01:48 AM

You have mail

02-10-2004, 03:01 PM	#1
chevyfan420 Registered User Join Date: Nov 2003 Location: Ancaster, Ontario, Canada eh Posts: 95	fuel gauge and/or sending unit troubles a couple days ago i switched my 79 back to gas from propane. i hooked the single wire for my gauge up to the wire coming from the sending unit and i bolted the ground wire from the sending unit to the frame. i poured a 5 gallon can in, started it up and my gauge read 1/4 tank. I thought ok, alright it works. later that day i put $25 in and my gauge never moved at all. the truck sat for a day. the next time i got in the gauge read 1/2 tank. i drove a bit and found a cheap station so i topped my tank up and it still reads 1/2 tank. later that day it reads a little under 1/2. does anyone have any ideas why its acting so screwy? does this sound like its my gauge or my sending unit? any help is greatly appreciated. ps: anyone near Ontario want to buy a complete propane setup? tank to carb, it fits on a regular 4brl spread-bore intake. __________________ 80 Chevy K10 350/350turbo 86 Chevy 1/2 ton shorty project truck 79 Chevy 1/2ton 350/350turbo not much to look at... *Retired* 97 Chevy C1500 4.3/5 speed.....daily driver

02-10-2004, 03:05 PM	#2
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	at the moment 3/8ths of a tank on the guage is a full tank. i have also had it 1/4 tank pass full as a full tank. check your grounds...then check float for corrosion where it would be making bad contact. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

02-10-2004, 03:43 PM	#3
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,774	Also your float may be stuck a bit. If you've not used it in awhile since you've ran propane then it might be stuck. If you have a 2nd tank fill it up as well and see if it works. If not then you know it the gauge. If it does then you know it's the tank wiring or sending unit. __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

02-10-2004, 06:54 PM	#4
chevyfan420 Registered User Join Date: Nov 2003 Location: Ancaster, Ontario, Canada eh Posts: 95	it only has a single tank. i pulled the sending unit out of the tank to check it ,blow the lines out and to clean it. the float seemed to be free. i think it has more to do with the gauge because it would register a reading while it was on propane. i checked and it was'nt hooked to my propane tank, so it was getting a signal (or whatever makes the gauge work) from somewhere. __________________ 80 Chevy K10 350/350turbo 86 Chevy 1/2 ton shorty project truck 79 Chevy 1/2ton 350/350turbo not much to look at... *Retired* 97 Chevy C1500 4.3/5 speed.....daily driver

02-10-2004, 09:41 PM	#5
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,774	Strange for sure. Wonder what the gauge was reading then while on propane? I've got a copy of a schematic of the fuel wiring system if you need it. __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

02-10-2004, 10:56 PM	#6
chevyfan420 Registered User Join Date: Nov 2003 Location: Ancaster, Ontario, Canada eh Posts: 95	yes, please send me a copy at: chevyfan420@hotmail.com __________________ 80 Chevy K10 350/350turbo 86 Chevy 1/2 ton shorty project truck 79 Chevy 1/2ton 350/350turbo not much to look at... *Retired* 97 Chevy C1500 4.3/5 speed.....daily driver

02-11-2004, 01:48 AM	#7
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,774	You have mail __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

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