Fuel Sending unit test ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Nvbowtie · 08-27-2003, 04:47 AM

Is there a way to test the Fuel Sending unit outside of the tank, I am ready to re-install my tank, but don't want to pay 80-100 bucks for a sending unit if I don't need to.

(I bought the truck not running, as I pulled everything apart, I removed the sending unit and put in a box for the summer rebuild of the truck )

87 STEPPER · 08-27-2003, 10:14 AM

The sending unit is nothing but a veriable resistor as it moves along the coil up for a full tank and down for empty the resistance will change.

Just get an ohm meter and find the wire that is for the V/R coil hook your + to the wire and your - to the sending unit housing and then move the float assy. and watch for a change in resistance value.

It my take you several times to find the proper scale value to select in order to get a reading on the meter.

Or you could just hook it into your trucks system and move the float assy. with pwr. on and watch the fuel guage to see if it respondes correctly.

Nvbowtie · 08-27-2003, 09:20 PM

Thats what I was thinking, just didn't want to kill it if it did work

Thanks Bruce

phantom dually · 08-27-2003, 09:25 PM

Whatever you do dont give it 12VOLTS!!! It will kill it FAST!!!!!

maineiac · 08-28-2003, 02:16 PM

2 things

1st you don't need pwr to check it a multi meter will read the change in resistance as you move the float up and down. To be sure it is right you would have to know the values but as long as it changes chances are you are ok.

2nd if you connect it to check it make sure you have it grounded or you won't get nothin.

Later

08-27-2003, 04:47 AM	#1
Nvbowtie Registered User Join Date: Jul 2001 Location: Laughlin, Nv. USA Posts: 700	Fuel Sending unit test ? Is there a way to test the Fuel Sending unit outside of the tank, I am ready to re-install my tank, but don't want to pay 80-100 bucks for a sending unit if I don't need to. (I bought the truck not running, as I pulled everything apart, I removed the sending unit and put in a box for the summer rebuild of the truck ) __________________ www.unlimited2u.com/chevy Bill 1980 Chevy C-10 Silverado 1988 Chevy Blazer Tahoe

08-27-2003, 10:14 AM	#2
87 STEPPER STILL PLAYS WITH TRUX Join Date: Nov 2002 Location: Melbourne, Fla. Posts: 2,764	The sending unit is nothing but a veriable resistor as it moves along the coil up for a full tank and down for empty the resistance will change. Just get an ohm meter and find the wire that is for the V/R coil hook your + to the wire and your - to the sending unit housing and then move the float assy. and watch for a change in resistance value. It my take you several times to find the proper scale value to select in order to get a reading on the meter. Or you could just hook it into your trucks system and move the float assy. with pwr. on and watch the fuel guage to see if it respondes correctly. __________________ ~~Bruce~~ MY 87 STEPPER MY 99 2D/WD TAHOE

08-27-2003, 09:20 PM	#3
Nvbowtie Registered User Join Date: Jul 2001 Location: Laughlin, Nv. USA Posts: 700	Thats what I was thinking, just didn't want to kill it if it did work Thanks Bruce __________________ www.unlimited2u.com/chevy Bill 1980 Chevy C-10 Silverado 1988 Chevy Blazer Tahoe

08-27-2003, 09:25 PM	#4
phantom dually Project92 SWB stepside Join Date: Feb 2003 Location: Louisville KY Posts: 4,793	Whatever you do dont give it 12VOLTS!!! It will kill it FAST!!!!! __________________ 92 C1500 stepside 496 Stroker Competiton Engineering Ladder bars/QA1 coilovers. Dana 60 rear with 4.10 gear and posi. Bonspeed Palisade 20x12 in rear w/335/30/20 and 20x8.5 front w/245/40/20. 5/8 drop with Belltech springs/DJM spindles/drop shocks. WWS Progress thread http://67-72chevytrucks.com/vboard/s...d.php?t=140448

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08-28-2003, 02:16 PM	#5
maineiac Registered User Join Date: May 2003 Location: South Carolina Posts: 104	2 things 1st you don't need pwr to check it a multi meter will read the change in resistance as you move the float up and down. To be sure it is right you would have to know the values but as long as it changes chances are you are ok. 2nd if you connect it to check it make sure you have it grounded or you won't get nothin. Later



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