Fuel System: 49 Champion gas gauge problem

[smithhn]

I installed a refurbished gas tank, new fuel lines and sending unit on my 49 Champion and I can't get the fuel gauge to work. I tested the wire from the gauge by grounding it to the frame no gauge movement. I put a 12v test light between the gauge wire and the ground and noticed a dim light, so I know some juice is getting through. I then checked the voltage at the sending unit and found 3.5 volts. Next I put a solid 6 volts to the gauge from the sending unit and got a full reading on the gauge. The only thing I can figure is that the gauge is sticking until it gets a more voltage.

Your opinion please, any input would be appreciated........Thank H Smith

[mkibler]

Fuel gauge dilemma

I installed a refurbished gas tank, new fuel lines and sending unit on my 49 Champion and I can't get the fuel gauge to work. I tested the wire from the gauge by grounding it to the frame no gauge movement. I put a 12v test light between the gauge wire and the ground and noticed a dim light, so I know some juice is getting through. I then checked the voltage at the sending unit and found 3.5 volts. Next I put a solid 6 volts to the gauge from the sending unit and got a full reading on the gauge. The only thing I can figure is that the gauge is sticking until it gets a more voltage.

Your opinion please, any input would be appreciated........Thank H Smith

Mr. Smith,

I posted a message about a very similar problem with the fuel gauge on my 1951 2R5 a few days ago and virtually everyone suggested that I check the ground. I understand that there is a 6 volt and a 12 volt version of the sending unit. Does your sending unit match the voltage on your truck? Also, are the two wires to the sending unit possibly reveresed?

I'll keep you posted on how my problem is resolved if you will do the same thing. I think we may have the same, or similiar problem.

Regards,

Mark in Ohio

[5brown1]

From what I have read I do not believe the voltage of the sending unit is important. What is important is the ohms rating of the unit and that it matches the ohms required by the gauge. After much experimenting I found that a modern 12 volt sending unit of 0-90 ohms was a perfect match for the 1939 Studebaker fuel gauge I have. I had assumed it was a 0-30 ohm gauge.
A voltage reducer (Runtz) is needed at the gauge when using the 6 volt gauge with a 12 volt system.

[smithhn]

Thanks for your input... Maybe I should've provided more detail... The gauge is the original unit and new sending unit is a stock 6 volt unit from a Studebaker supplier. I installed a ground wire to the frame when I installed the new sending unit. When I ran a test ground wire to several other locations at the rear of the car (trunk latch, bumpers, etc.) the gauge still didn't move. The lights all work, so I'm pretty sure I have a good ground at the locations tested. I did notice that when I was able to peg the gauge to full by putting the 6 volts to the gauge through the sending unit wire, the gauge needle would hang up in spots on the return. I needed to bump the gauge panel to release the needle to empty position. That's the reason I'm thinking it's the gauge. I was hoping it isn't the gauge because it's a real "booger" to remove. Thanks again for your input.... Howard S.

[kxet]

Don't put voltage to sending unit side of guage, It works by grounding through that side. What does it show when it lights test light? Measure ohms on test light. My sender reads 2 0hms full, 60 empty. Mine is a 49 Champion.

[smithhn]

Thanks all ... I think I've found my problem. I created a independent circuit through the gauge and can peg the gauge on a full reading, with the ignition off, with 6 volts. I'm pretty sure power is not getting to the gauge from the ignition. Don't have an ohm meter, per your instructions, I'll check that out as soon as I can lay my hands on one.

[StudeRich]

Be VERY careful putting Powered up jumper wires where they don't belong!

This Usually blows the Dash Unit totally out, there are VERY FINE Coils pulling on each side of the needle, and those ARE Fragile!

There is NO 6 or 12 Volt "Power" and should Never be, to ANY sending unit, only a variable OHMs resistance ground from it, to the Dash Unit.