Fuel Gauge reads 1/2 when full - TriFive.com, 1955 Chevy 1956 chevy 1957 Chevy Forum , Talk about your 55 chevy 56 chevy 57 chevy - Belair , 210, 150 sedans , Nomads and Trucks, Research, Free Tech Advice

Doug Harrell · 10-11-2006, 09:45 AM

Hi everyone, My gas gauge is only reading half full when the tank is full. I tested the gauge by leaving the sender wire hang free and the gauge goes to empty and when I ground it to the frame it goes to above full. I installed a new sender in the tank and added a extra ground wire from the sender to the frame. I also replaced the wire from the tank to the gauge. I replaced the power wire to the gauge, I have a good 12 volt connection. Have I missed anything that I could checked before I start bending the float arm on my new sender or is there another way to check the gauge.
Thanks Doug Harrell

MikeKy55 · 10-11-2006, 11:01 AM

Actually I think you will be straightening the float arm rather than bending it. Given everything you posted, the float arm would just about have to be bent.

dseale4888 · 10-11-2006, 06:11 PM

Mikes got it right as far as I'm concerned. The arm must be bent up from where it should be.
Dave

Doug Harrell · 10-12-2006, 07:24 AM

Thanks for the reply that was going to be my next move unless someone had another idea. Doug Harrell

dseale4888 · 10-12-2006, 07:06 PM

If you take the sending unit out plug it in and try moving the arm from one extreme to the other while watching the gauge move. That would narrow the problem down. If you move the sender to where it should be full and the gauge doesn't read correctly you know that it most likely would be the gauge then.
Dave

Doug Harrell · 10-14-2006, 07:55 AM

Thank's Dave ,I should of done that first when I got the new unit but I will try it when I pull it out again.
Doug

crashbodyman · 10-18-2006, 12:52 AM

If you reused your old brass float with your new sending unit the old brass floats sometimes develop holes and allow gas to seep inside which displaces the air in the float. The float never comes all the way up to the top.

radtechandnurse · 12-29-2006, 06:26 PM

need to make sure sending unit has a good ground... check out ol 55 east coast chevy site they have tips on it there!

edcat57 · 02-17-2007, 09:25 PM

Sounds like you did a great job setting it up. Check for full travel of the float arm. I had a brand new unit from Classic Chevy International that would stick about half way down. It made for some serious speculation on long trips. You can also check the sending unit with an OHM meter. Connect the positive lead of the meter to the stud for the gauge wire, and the negative lead to the mounting plate. Moving the arm one way should give you a reading of 0 Ohms, and movine it the other way should give you about 30 Ohms. If everything checks out, bend the arm.

rrs57 · 02-19-2007, 10:44 AM

my 57 does the same thing i put in new sending unit from c.c.i. when i built that car 12 years ago it shows 1/2 tank when full i keep it around a 1/4 of a tank if it ever happens to get down to empty your just rolling the dice as to when you run out. i also think it is a bent float arm i should fix mine but i have more cars and projects than i have life but maybe some

day i will get to it at least i have a gauge that works so many cars never get theirs working. the gas gauge for my backhoe is a yardstick gets to 2 inchs time to refuel cant measure car tanks like that would be a lousy system anyway rob

10-11-2006, 09:45 AM	#1
Doug Harrell Member Join Date: May 2006 Doug Harrell's Garage Location: MD Posts: 75 Member #557	Fuel Gauge reads 1/2 when full Hi everyone, My gas gauge is only reading half full when the tank is full. I tested the gauge by leaving the sender wire hang free and the gauge goes to empty and when I ground it to the frame it goes to above full. I installed a new sender in the tank and added a extra ground wire from the sender to the frame. I also replaced the wire from the tank to the gauge. I replaced the power wire to the gauge, I have a good 12 volt connection. Have I missed anything that I could checked before I start bending the float arm on my new sender or is there another way to check the gauge. Thanks Doug Harrell

10-11-2006, 11:01 AM	#2
MikeKy55 Administrator Join Date: Dec 2005 MikeKy55's Garage Location: Mt Washington Ky Posts: 4,385 Member #10	Actually I think you will be straightening the float arm rather than bending it. Given everything you posted, the float arm would just about have to be bent. __________________ ''Thank a police officer for being the one who runs to a report of 'Shots Fired' while others run away.'' http://www.youtube.com/watch?v=8QuJeYqNzew

10-12-2006, 07:24 AM	#4
Doug Harrell Member Join Date: May 2006 Doug Harrell's Garage Location: MD Posts: 75 Member #557	Gas gage reads half full Thanks for the reply that was going to be my next move unless someone had another idea. Doug Harrell

10-18-2006, 12:52 AM	#7
crashbodyman Member Join Date: Aug 2006 crashbodyman's Garage Posts: 4 Member #993	gage reads half full If you reused your old brass float with your new sending unit the old brass floats sometimes develop holes and allow gas to seep inside which displaces the air in the float. The float never comes all the way up to the top.

02-19-2007, 10:44 AM	#10
rrs57 Senior Member 1 Blue Star Join Date: Nov 2006 rrs57's Garage Location: oklahoma Posts: 270 Member #1382	gas gauge my 57 does the same thing i put in new sending unit from c.c.i. when i built that car 12 years ago it shows 1/2 tank when full i keep it around a 1/4 of a tank if it ever happens to get down to empty your just rolling the dice as to when you run out. i also think it is a bent float arm i should fix mine but i have more cars and projects than i have life but maybe some day i will get to it at least i have a gauge that works so many cars never get theirs working. the gas gauge for my backhoe is a yardstick gets to 2 inchs time to refuel cant measure car tanks like that would be a lousy system anyway rob

10-11-2006, 06:11 PM	#3
dseale4888 Senior Member 4 Gold Stars Join Date: Feb 2006 dseale4888's Garage Location: North Attleboro,Ma. Posts: 4,665 Member #228	Mikes got it right as far as I'm concerned. The arm must be bent up from where it should be. Dave

10-12-2006, 07:06 PM	#5
dseale4888 Senior Member 4 Gold Stars Join Date: Feb 2006 dseale4888's Garage Location: North Attleboro,Ma. Posts: 4,665 Member #228	If you take the sending unit out plug it in and try moving the arm from one extreme to the other while watching the gauge move. That would narrow the problem down. If you move the sender to where it should be full and the gauge doesn't read correctly you know that it most likely would be the gauge then. Dave

10-14-2006, 07:55 AM	#6
Doug Harrell Member Join Date: May 2006 Doug Harrell's Garage Location: MD Posts: 75 Member #557	Thank's Dave ,I should of done that first when I got the new unit but I will try it when I pull it out again. Doug

12-29-2006, 06:26 PM	#8
radtechandnurse Member Join Date: Nov 2006 radtechandnurse's Garage Posts: 3 Member #1496	need to make sure sending unit has a good ground... check out ol 55 east coast chevy site they have tips on it there!

02-17-2007, 09:25 PM	#9
edcat57 Member Join Date: Feb 2007 edcat57's Garage Location: St. Simons Island, Georgia Posts: 5 Member #2018	Sounds like you did a great job setting it up. Check for full travel of the float arm. I had a brand new unit from Classic Chevy International that would stick about half way down. It made for some serious speculation on long trips. You can also check the sending unit with an OHM meter. Connect the positive lead of the meter to the stud for the gauge wire, and the negative lead to the mounting plate. Moving the arm one way should give you a reading of 0 Ohms, and movine it the other way should give you about 30 Ohms. If everything checks out, bend the arm.

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