[divotandtralee]

In the spirit of "fixin" in a throw-away world.. I got my sender back to performing as new. To share my experience, the gauge on my '73 SPICA Spider would read ok from FULL to 1/2 and then would trip OFF to below zero as the tank got below 1/2.. just a big jump without a RESERVE light.
Prised the three tabs holding the plastic cover (careful..only enough to wiggle the cover off) and discovered how simple the sender was. I had rebuilt Giulietta sneders and this was like so simple I couldn't believe my eyes. The "sweeper" inside rides on a black banded potentiometer that varies the resistance and register s the accurate level on the gauge. The tip of the sweeper which makes the contact has a "nipple" that wears out and the result is a hole where the nipple was. The arm makes contact without the nipple in the first half of the tank level but loses contact in the lower half. The solution is to thread a piece of 18 ga. copper wire through the hole and soldering on the wire with the side of the wire acting as the nipple. It is important to use the smooth side of the wire as the riding surface to "skid" across the potentiometer. You cannot use the end of the wire like a stylus or it will hang up on the potentiometer wrappings (ask me how I know)...It's a cool victory.. Last thing to do is wipe the potentiometer with 1500 sand paper to clean of any gas deposits... Everything including the RES light works to a tee.

 

[gregeast]

Excellent, well done sir!

 

[divotandtralee]

Ca't say I "invented" this solution . It was probably published here 15 years ago.

 

[divotandtralee]

What you should look for is a donut hole at the end of the sweeper contacting the potentiometer. The hole is the nipple that has worn away leaving only a hole but still has intermittent contact which is not enough friction to hold it steady and the result will be a bouncing reading even in the top of the gauge range. It is through this hole you curl the wire through flattened on the arm to receive solder it in place. Heat the ARM of the sweeper with your soldering gun boiling the flux paste and apply the solder. Do not try to melt the solder to a cold substrate.. the arm. It will just bead off like mercury and you will get frustrated.. Polish the arm where you are soldering to. When you are done, the float arm should travel through the whole range with the sound and feel of a fine zipper..

 

[velocedoc]

This is a great fix. In my case, what do you do when the wire breaks? It appears to be Ni-chrome wire.

 

[divotandtralee]

I suppose if it was the last sender on earth, I would find a solution but there is an 'end of the road" for everything. Even Pat Braden, the king of using up parts to the bitter end of their life would concur. If you still want to investigate your options, I would stroll down to your electronics repair geek. We have a grey haired guy here on Cape who has a man-cave shop filled to the rafters with everything that is audio and video that he is working on. It's like the old shoemaker shop where you walk in to claim a pair of shoes that were resoled and 3 minutes later the cobbler pulls them out of a rack ready to go and a mountain of pairs in the queue. The geek will tell you if it is fixable.. I kind of doubt it is worth the trouble.