testing task force fuel gauge

[lowrodderchev]

Hey gents is there a way to test the fuel gauge in a TF truck? I hook the power up and brand new sender nada nothing moves I hooked up 2 different gauges that I have and nothing, please help me..........

[OrrieG]

Power goes to one post of the gauge. Other post wire runs to the sender which is a potentiometer that acts as a variable ground to move the gauge. If the tank is empty gauge reads that way. If you have a new relocated tank and the gauge goes really hard to full and does not come off until the tank is only 1/4 full you have a late model sender (90 ohm if memory is right) going to a gauge set up for stock 30 ohm. Test for the gauge would be to get a know good sender and bench test it unless you have some potentiometers setting around. Ogre will be impressed that I remembered the right term this time!

[lowrodderchev]

I'm running a mustang tank but installed a new 0-30 ohm sender I have 5 gallons of gas in a 16 gallon tank I just notice the needle dont move at all if I unplugged the sender from the gauge shouldn't it move?

[1project2many]

When the sender is disconnected the needle should move above full. When the sender wire is connected to ground the needle should show less than empty.

You might have to install a ground wire between the tank and the chassis.

[lowrodderchev]

with power my gauge don't move at all so probably faulty gauge

[1project2many]

Probably so.

[mr48chev]

I think that If I still had the stock tank laying around I'd pull the sender out of it and after checking it with an ohm meter to make sure that it worked hok it to the wire running from the gauge to the sender and ground it and run the float lever though it's travel and make sure that the gauge worked.

I would then pop the Mustang sender out and hook an ohm meter to it and run the float through it's travel to make sure that it works properly. On a lot of sending units there is a tab on the body to connect a ground wire to to run it back to a good ground as the tank may be somewhat insulated from the frame by padding under the straps.

I was sure that the Chev trucks had a 90 ohm sender but this Eckler listing shows theirs to be 30 ohms http://www.ecklerstrucks.com/chevy-t...1954-1959.html

The sender acts as a variable resistance ground for the gauge in the dash as the power to the gauge is fed to and through the gauge and then runs from the gauge to the sender which serves as the ground.

I was fairly positive that "all" normal GM vehicles used a 90 ohm tank sender but that may have come at a later date than I thought. You still have to make sure that the Ford sender has the same ratings for empty through full as the trucks unit does and doesn't read backwards.

[OrrieG]

I think they changed from 30 to 90 in the 60's. I had a 68 chevelle tank as an auxillary and hooked up the float to my stock gauge thru a toggle switch. The stock tank would read ok, the aux would peg and stay there until I had about a 1/4 tank left. I always ran the aux down first then switched to the main so I did not get surprised back in the boonies with only 1/4 tank of fuel.

[lowrodderchev]

I cut a hole on the top of my tank to run a gm style 30 ohm sender so the mustang isn't used only for the gas line. I have a gauge from my blazer lying around so I ran it to see what would happen it marked not correct but it marked