Instrument voltage reducer

[rsrose]

Does the 1962 GMC 1000 Series have one or two Instrument Voltage Reducers on the back side of the original instrument cluster? This part, if it exists, is also called an Instrument Voltage Limiter or a CVR (Constant Voltage Regulator). Again, if they exist, who has them?

[James]

The 1962 manual does not show any voltage reducer(s) for the instrument panel or anywhere on the truck.

What is the problem are you having?

[rsrose]

New sending unit in gas tank, grounded correctly, but gas gauge always shows 3/4 full even with the tank empty or full.

[James]

Let do some basic troubleshooting. Disconnect the wire from the sending unit. With the wire disconnected, what does the gauge reads? Then place the wire directly to ground, what does the gauge reads?

[rsrose]

James,
Disconnecting the wire from the post of the sending unit, the gas gauge needle goes all the way to the right, or to full.

Touching the wire to the ground sends the needle all the way to the left, or to empty.

[AZKen]

Sounds like it passed those tests, so next question: What does needle do when ignition is OFF?
You can have a stuck float, stuck needle, bad sender or bad gauge.

Also: Why are you just now noticing that? What have you done wiring wise and what have you replaced recently? Please give part numbers and vendor name of any parts recently replaced. Give description of any work/wiring done.

1. Sending units are not voltage specific but require correct ohmage.
2. Gauge is voltage and ohm specific.