Fuel Gauge Question

[Cold Blue]

Trying to get my original gas gauge working....Installed my new 2 wire sending unit. Hooked everything up. Car is 12 volts so I hooked up a Runtz converter to get 6 volts. Checked that with my multi meter. Yep, 12 at the runtz, 6 at the gauge. Dash gauge is non responsive!! Reversed the wires at the sender. Still no dice.  Here is my question. -  When I took the gauge out of the dash and looked at it carefully, the needle was on the outside of the right hand coil, keeping it locked in the "Full" position. I did not think that was right, so I carefully got it past the coil so the needle was "free floating" between both coil parts. My thinking was that the needle should read "Empty" when the key was off, not "Full". The needle could then rotate freely between empty and full. I thought that was correct. Was I right in doing that? Or should the needle be on the outside of the right coil like it was when I first removed it? Did I screw up?  Please help me. Thanks!! (I searched the Forum for an answer, first, but couldn't find anything..)

[soth122003]

Hey Cold,

Pull the gage out and check for any obvious damage. I believe the needle should free float. Then check the contact points on the gage for sticking. Clean with a points file or emery cloth. The picture in the Plymouth manual sucks so here is one from the Motors manual.  Sorry for the focus on the sender pic, but it is mostly self explanatory.  Also I would spray the whole thing with contact cleaner to get the crud off if any is on there. 

 

Joe Lee

Edited April 19, 2019 by soth122003

[Cold Blue]

Wow! Thanks Soth! I will pull her out and clean the points and spray her down. I agree - the diagram shows the needle in free float - that makes me breathe a sign of relief. With the diagram I can check everything out. Thanks so much!

[soth122003]

Not a problem Cold. I remember how frustrated I was trying to look at a darkened diagram and since buying the motors manual and with the ageing eyesight, a set of magnifying lenses works wonders.

 

Joe Lee

[Cold Blue]

20 minutes ago, soth122003 said:

Not a problem Cold. I remember how frustrated I was trying to look at a darkened diagram and since buying the motors manual and with the ageing eyesight, a set of magnifying lenses works wonders.

 

Joe Lee

I have the ageing eyesight problem too. I had really good close vision until about a year ago - reading glasses are my friend now. I think I found the problem..I took the gauge out, filed the points with my points file, and gave her a good spraying with contact cleaner. Then noticed something - the heating coil on the right side - the fine wires are bridged with rust gobules along most of its length.  The left side is fine. I am going to put some power to it while I have it out and see if the heating coils get warm at all ...I am afraid I need a new gauge...

[Cold Blue]

Uh - oh...Put some power to the unit, with the sensor leads attached, and the heating coils stayed stone cold. New gauge required. Oh well, I learned one more thing about my 48. That is valuable to me. Thanks again, Joe Lee.

[Richard Cope]

I am converting my car to 12 volt.  I recently sent my 6 volt fuel gauge to D&M Restoration (800-722-0854).  They put the  face plate from my gauge on a 12 volt GM gauge, fits into the original gauge cluster and looks stock.  I already had a 0-90 Ohm sender for the tank.  With this set up it is an easy one wire connection between the sender in the tank and gauge.

[Cold Blue]

1 hour ago, Richard Cope said:

I am converting my car to 12 volt.  I recently sent my 6 volt fuel gauge to D&M Restoration (800-722-0854).  They put the  face plate from my gauge on a 12 volt GM gauge, fits into the original gauge cluster and looks stock.  I already had a 0-90 Ohm sender for the tank.  With this set up it is an easy one wire connection between the sender in the tank and gauge.

Dadgummit - I have already bought a NOS original fuel gauge, (its on it way..) I have already bought a repro 2 wire sender, and installed it. Already ran another wire from the sender to the gauge cluster. Wish I had not been so impatient. Your way of doing it would have been so much easier, and probably cheaper. A lot less labor too. But at least I can say that all the pieces/parts are like they were when it was built, if thats any consolation....

[soth122003]

Hey Cold

Found this pic also.

 

Joe Lee

[Cold Blue]

18 hours ago, soth122003 said:

Hey Cold

Found this pic also.

 

Joe Lee

Thanks Joe! With your help I feel like I understand how these things work. Everyone talks about how simple these cars are, but this gauge, to me, ain't that simple!!!