57 Belvedere gas sender grounded?

[Rusty Muffler]

Hi again all, just getting my car running and discovered the gauge well below empty with 5 gallons in the bone dry tank. I took the wire loose at the sender and grounded it and the gauge reads about 2/3 full (should read full). I did the same under the dash at the gauge and same thing so I know the gauge is good but doesn't read correct. By now I put 5 gallons more in so I would have some reading above empty so I wouldn't have to worry about running out of gas. Well the gauge read the same, below empty. So I tried a ground jumper from the bumper to the tank and now the gauge reads on the circle for empty, not below. Was there some sort of ground strap for these cars or can I add one? If so, what do the look like and where can I find one? Also is there a way to make the gauge read right?
Thanks!!

 

[Big_John]

Hi again all, just getting my car running and discovered the gauge well below empty with 5 gallons in the bone dry tank. I took the wire loose at the sender and grounded it and the gauge reads about 2/3 full (should read full). I did the same under the dash at the gauge and same thing so I know the gauge is good but doesn't read correct. By now I put 5 gallons more in so I would have some reading above empty so I wouldn't have to worry about running out of gas. Well the gauge read the same, below empty. So I tried a ground jumper from the bumper to the tank and now the gauge reads on the circle for empty, not below. Was there some sort of ground strap for these cars or can I add one? If so, what do the look like and where can I find one? Also is there a way to make the gauge read right?
Thanks!!

The easiest way to add a ground is to run a wire from a good ground and then take a small hose clamp and attach it to the tube coming out of the sender.

Get that under control first and then take a look at the sender.

Ultimately, you can make corrections with a Meter Match. TechnoVersions - MeterMatch for Analog Gauge Correction and do a search here on the forum as a few of us have used it. Before you add anything like that, work on getting everything right with wiring and grounds.

 

[57fury440]

Do what Big_John said. The inaccurate reading could be the float. I changed the float in mine about two years ago and I get a pretty good reading now. Mine came with a cork for the float and it was not floating anymore. Ace Hardware sold different size corks and I used one of theirs. Before I did that I purchased a new sending unit which was not good.

 

[Fireflite56]

Do what Big_John said. The inaccurate reading could be the float. I changed the float in mine about two years ago and I get a pretty good reading now. Mine came with a cork for the float and it was not floating anymore. Ace Hardware sold different size corks and I used one of theirs. Before I did that I purchased a new sending unit which was not good.

Did you coat the cork with anything like the original or just stick it on there as-is?

To the original poster: you can test the float theory by removing the sending unit from the tank and with it grounded out properly and the gauge wire hooked up (you'll probably have to be under the car holding the sending unit at this point), have someone turn on the key and monitor the gauge as you manually move the arm from complete full to empty. If the gauge reads correctly, it's likely your float. If the float is one of the brass kinds and has become saturated through a small leak, it's pretty easy to feel that it's full of gas and not empty. The cork is a little harder to tell just by looking at it.

 

[57fury440]

I didn't coat the cork, I just put it in.

 

[mikes2nd]

tank has to be grounded...thats first