Fuel gauges don't work

[class87]

From: RickCarol1  (Original Message)
Sent: 3/27/2005 8:58 PM

does anyone have any ideas of what i can check?




From: Sea Hag
Sent: 4/3/2005 12:19 PM

From your pics I see you have a 73 Indian . ( posting the year and model helps narrow things down ). There is some good info on the gauges if you search "voltage limiter " This limiter is ususually the problem . A good ground is important too on the Printed circuit type dash .        Sea Hag 



From: denison
Sent: 4/3/2005 3:07 PM

there are several threads about this problem.
If the voltage limiter is bad, the fuel gauge would not read right, but neither would the temperature and oil pressure gauges. With the ignition on they all get a pulsed voltage from the limiter, 12 volts-to-off-to-12-volts-to- off, that averages to about 5 volts. It was a common scheme during the 50s on cars. Due to the pulse rate being about 1 second, and the typical sampling rate of inexpensive VOMs, I would use an analog multimeter to measure the voltage limiter output. Also the limited would be quite warm if the ignition was on.
If its only the fuel gauge that is not working, the suspect would be a bad wire from the sending unit mounted in the top of the fuel tanks, or a bad sending unit inside the tanks. The sending units are still available - I got my last one from J.C.Whitney. Dropping the tank and replacing the sending unit is more a job several of us have had to do. The rest of the members will have to do it eventually.
You could substitute a resistor of about 30 ohms and several watts. The fuel level sender units have a resistance range of about 3 to 90 ohms. I think the lower resistance indicates a full tank, because if you ground the wire from the sending unit briefly - the fuel gauge shoots up past "F". I think so anyway.
By the way, is your dashboard the one with the circular instruments cluster, or the kind with the instruments lined up in a row along with the linear speedometer?

[DanD2Soon]

From: DanD2soon
Sent: 4/4/2005 3:05 PM

This link may help explain / adjust / fix...

http://www.allpar.com/history/mopar/electrical2.html

DanD