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I bought a conversion kit from shift works for fuel and bat. on the fuel gauge, oil and temp in the clock space. The fuel gauge didn't work. I checked the sending unit and the wire that runs to it. There both good. I put the old gauge in and still nothing. With the key in run position it came up but when I started the engine it dropped back down. I ran a seperate ground to the instrument panel housing and still didn't work. Any idea what I'm missing?
 

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I would start with grounding the wire at the sender in the back and turn on the key,this should peg the gauge on full.If this works the wireing from the tank to the gauge is good.if not try grounding the wire that comes from he tank right at the gauge and tune key on,pegged guage means the gauge is good and the wiring is an issue.If things are dead further diagnosis will be required.I have seen the guages you describe but have never seen the backs of them or how they are wired if different than OEM.What did they come with in the way of instructions?
 

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I bought a conversion kit from shift works for fuel and bat. on the fuel gauge, oil and temp in the clock space. The fuel gauge didn't work. I checked the sending unit and the wire that runs to it. There both good. I put the old gauge in and still nothing. With the key in run position it came up but when I started the engine it dropped back down. I ran a seperate ground to the instrument panel housing and still didn't work. Any idea what I'm missing?

When you "checked" the sending unit and the wire that runs to it, how was this checked (visually or electrically) ?

Most gauges like a fuel gauge require an ignition 12 volts, a good ground, and a variable input from the sender (as well as the sender also having a good ground). If any of these are poor or non-existant, the gauge will not work or work improperly.

To get more familiar with how the fuel gauge system works, do a search here on this site. There have been many, many, many threads with info in them. Once you become more familiar with the system then it will become easier to troubleshoot and repair the problem(s).

Just to keep things straight, if you have 12 volts and ground to the gauge and NOTHING connected to the terminal for the sending unit then if the gauge is working the needle should be at the full or above mark. This however is only part of a test that needs to be done. When the sending unit terminal is then grounded, then if the gauge is good the needle should swing to the empty or below mark. When nothing is connected to the sending unit terminal then the gauge see's more than 90 ohms of resistance and when grounded the gauge see's 0 ohms of resistance.

When you do your searches and reading you will also see that GM used 0-30 ohm systems and 0-90 ohm systems and these parts all have to work together as a set. You cannot use a 0-30 sender with a 0-90 ohm gauge and expect it to read properly.

Jim
 

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The kit uses the stock plug for the sending unit and includes a jumper that feeds the battery and temp guages. Oil is mechanical. I checked the sending unit with a meter reading the ohms while I moved the float. I also checked continuity on the wire from the tank to the guage. I also swapped out the new guage with the original and got the same result. Ill try reading the ohms with engine off and then started and see if the resistance changes
 

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I bought a conversion kit from shift works for fuel and bat. on the fuel gauge, oil and temp in the clock space. The fuel gauge didn't work. I checked the sending unit and the wire that runs to it. There both good. I put the old gauge in and still nothing. With the key in run position it came up but when I started the engine it dropped back down. I ran a seperate ground to the instrument panel housing and still didn't work. Any idea what I'm missing?
Recheck your grounds at dash...
 

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I guess the big question is did it work before you started all of this?

Somewhere down the line a wire may be plugged onto the back of the ignition switch in the wrong place.

Ohm between the frame of the car and the ground strap terminal on the sender.

Steve
 

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I checked the sending unit with a meter reading the ohms while I moved the float. I also checked continuity on the wire from the tank to the guage.
What were your readings on this ?

Have you checked to see if you have an ignition 12 volts to the gauge as well as a ground from the gauge to the body of the car ?

Jim
 
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