Bad gass guage 1948 Plymouth Special Deluxe

[Bern Pearson]

I have a 1948 Plymouth Special Deluxe.  The gauges work except for the fuel gauge.  I started going through the archives looking for troubleshooting information.  Is there a way to search the trouble shooting archive?

 

The gauge sometimes reads empty and sometimes full.  Neither is usually correct.  Any advice is appreciated.  Thanks.

Bern

 

 

[plymouthcranbrook]

Make sure your tank has a good ground. Also you can check the sender by removing it from the tank and with the ignition on move the float throughout its range of motion. The gauge should go from full to empty smoothly.  If it works the problem might be the float.  Otherwise check the connections on the back of the gauge and continuity of the wire to the sender.

[Jerry Roberts]

If you do the above test , make sure that you ground the sender body . 

[John Reddie]

Hello and welcome. Yes by all means, make sure the sender has a clean ground connection. A poor ground could certainly produce symptoms like you a describing. Good luck to you.

John R

[greg g]

First and easiestthings to do, 

 

Check under the dash make sure there is no unintended path from the gauge terminals to ground.  I had a defroster duct fall down on mine and the wire stiffener grounded the gauge so it showed full all the time.

 

Make up a dedicated ground wire from one of the screws on the sending unit  to one of the screws that holds the cover to the trunk floor.

 

If your car doesn't have a ground strap or wire from the body to ground make up one from a fire wall bolt to the engine, bell housing or frame rail.  If you get lucky you won't need to spend big bucks on a new sending unit.

 

[Bern Pearson]

Thank you for your responses.  I have been in the hospital since asking the question but I am out now.  The tank is off and drained.  Then tank is full of junk, which appears to have clogged the "self cleaning" finlter.  But, otherwise, appears to be in good condition.  The sender unit looks as though it has seen better days, which apparently ended in the late sixties.  

 

Does anyone have a source for a new sender unit?  It is the 17 gallon tank.  

 

Again, thanks.

 

Bern

[greg g]

eBay. Make sure the one you get has the same number of wires as the original.  Gld you are up and at it again.

[Bern Pearson]

Whoo-hooo!  I took off the tank and filled it with water and a gallon of Muriatic acid.  After a night, I cleaned and cleaned and cleaned again.  (Used plenty of Dawn detergent.)  The tank ended up beautiful.  I cleaned the lines, filter and the carb.  

 

I got the gas gage to work properly.  The new one, off eBay, looked nothing like the old one which I suspect was from a Chevy.  

 

Thanks for the help. 

[Richard A]

Last time I cleaned out a tank I used a quart of Por-15's Marine Clean, 1:1 with hot water.  Left the tank in the bed of my truck for a couple of days, threw in a handful of fine gravel for scrubbing action and it was spanky clean in a few days.  Por 15 changed the name of the product since then, but it's still available under a different label.