66 valiant gauges

I BELIEVE your gauge cluster still has the instrument regulator built into the fuel gauge. If the fuel gauge has THREE terminals that's what you have

The "condenser thing" is a radio suppression cap

Here's how all Mopar gauges work, and you need to think of them like a "system"

The ignition switch sends power to the cluster harness connector, which supplies power to various things depending on the year/ model

Brake warning switch, oil warning lamp, etc, and the INSTRUMENT VOLTAGE LIMITER, or called by other names.

This is either a rectangular box about 3/4" X 2" long, or it's built into the fuel gauge.

This receives 12V switched ignition from the panel harness connector, and regulates power to the gauges "to simulate" about 5 volts. I say this because the originals work exactly like a flasher---they pulse 12V on/ off and these pulses do not show in the gauges because the gauges don't react that fast.

So this limiter power comes OUT of the limiter and jumpers over to the temp gauge and the oil gauge if you have one.

On cars with a "plug in" limiter you need to check that the limiter is good and that the PC board connector is making contact (later models)

The power goes to the gauge studs---and so you must make sure the studs make contact

Out of the sender end of the gauges, the sender wires go back through the cluster connector and off to the senders and to ground

QUICK CHECK

Disconnect the temp and fuel senders and clip them to ground. Turn the key on for a short time and watch the gauges. If neither gauge reacts, it's most likely the limiter.

There "are people" who repair these, and if you Google around, there's a repair procedure

RTE also sells replacement solid state limiters

http://rt-eng.com/rte/index.php/RTE_Limiter_Faq

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

http://www.moparmusclemagazine.com/techarticles/interior/23241_instrument_gauges_repair/viewall.html

http://1962to1965mopar.ornocar.org/ml-instrument-voltage-regulator64.html

http://www.forabodiesonly.com/mopar/showthread.php?t=86097