fuel gauge not reading gas at all

[BigFlo]

On our legacy Mopars (55-75) if one has a fuel guage, water temp and oil pressure guages they have a voltage limiter. The voltage limiter takes the 12VDC and outputs 5VDC. Note all of the mentioned guages are actually a 5VDC guage, and each respective, sensor is a variable resistor adjusting the guage indication...

You were saying gauge and I was thinking dummy light. I think Jerry set us straight!

 

[Michael Maresca]

The trick to that answer is a 67 GTX didn't have a gauge from the factory, so oil pressure is not related.

I wish I knew how to send pics. My so. Did anything I had posted in the past. But I do have what appears to be a factory idiot light that says oil pressure above it next to the Alternator gauge. It is on the right side next to the Alt. Gauge.

 

[Jerry Hall]

I wish I knew how to send pics. My so. Did anything I had posted in the past. But I do have what appears to be a factory idiot light that says oil pressure above it next to the Alternator gauge. It is on the right side next to the Alt. Gauge.

Yes it's a light and the oil sending unit is a switch. Turn on the ignition and the light comes on. Start the engine and the oil pressure turns off the switch. So 12V and ground are all that's involved in that circuit, not any voltage limiter. Your temperature and fuel gauges are resistor type circuits that are regulated by a resistance value against the 5V on the gauges to determine a needle position of the gauges. Hope this helps, because I know no way to take a picture of how they work.