Smiths Fuel Gage Troubleshooting

OVERVIEW:

Several Smith designs were used over the years.  Variously, they required two different resistance ranges.   A page from ERA's Wiring Primer is posted here with the testing procedure.

The Smith gages require a signal from the sender as shown below:

Late

 Tank empty - 240 ohms
Tank full - 25 ohms

Early

 Tank empty - 400 ohms
Tank full - 50 ohms

Some senders do NOT require a power connection to the pink wire in the harness.
Imediately below: Gages from early ERAs.   May be either range.
From 2011
Installed in 2011		Smith, chassis 2051
Installed in 2051
Below:  Two of the later-style gages.
Smiths, version 2
No rear markings		Smiths, version 3
Caerbont brand