871 Fuel Gauge

[WWP]

I've got a 1959 871 (6 volt) with a broken fuel gauge. I replaced both the gauge (310948) and the sender (310940) and it just reads empty. If I pull the sender connection it reads full.I've run direct grounds and triple checked the connections. I'm wondering if these parts aren't compatible.

Any help would be appreciated.

 

[Dean]

Some (all?) of the aftermarket sending units are not compatible with the OEM gages and vice versa.

The sending unit must be properly grounded to the chassis for proper operation.

Dean

 

[Norm Graves]

Does the float have a hole in it?

 

[WWP]

Nope, it is plastic and the wire has a loop that holds it in place.

 

[WWP]

I've run direct grounds to the sending unit and the gauge as well as setup on the bench with everything wired together.

 

[JMOR]

(quoted from post at 17:40:06 06/13/11) I've run direct grounds to the sending unit and the gauge as well as setup on the bench with everything wired together.

he sender is a resistor who's value depends on float rod position. As resistance changes, the current through the meter changes, thus the Empty/Full reading. I have seen senders who's resistance is 5 ohms to 50 ohms over the E/F range, others 20 to 80 ohms, others as high as 250 ohms. Further some have high resistance correspond to Full while others have high resistance correspond with Empty. The meter & sender and 6v/12v all need to match up. But whatever you have, matched or not, I expect you to see some meter movement with sender movement.

 

[WWP]

I don't remember exactly but I think it goes to 150 ohms when on
empty and almost zero when full. I had the same problem with the
first gauge I got so I ordered another and it does the same thing. I
guess it's possible the second gauge is bad as well. They come in a
resealable package so someone hooking to 12V might have blown
them up and sent them back?

 

[WWP]

I think that the gauge was misconfigured at the factory. I took the cover off and set it up on the bench with the gauge front off. With no stops in place it worked like it was supposed to. The real problem was that it goes to full position with no power applied. It was set to read empty with no power so it couldn't move counter clock wise past the stop when power was applied. I reset the gauge to full with the power off and it works. The range isn't perfect, probably 3/4 scale but good enough. I'd guess the sender isn't a perfect match.

Thanks for all the input.

 

[JMOR]

(quoted from post at 09:25:31 06/27/11) I think that the gauge was misconfigured at the factory. I took the cover off and set it up on the bench with the gauge front off. With no stops in place it worked like it was supposed to. The real problem was that it goes to full position with no power applied. It was set to read empty with no power so it couldn't move counter clock wise past the stop when power was applied. I reset the gauge to full with the power off and it works. The range isn't perfect, probably 3/4 scale but good enough. I'd guess the sender isn't a perfect match.

Thanks for all the input.

like that kind of perseverance!!!