no dash lights

Corrosion of the instrument light power source pin & socket can cause a poor connection at the circuit board connector. Corrosion severe enough at these connections can cause cross circuiting.....example high beam lights can blink when a blinker is used when a blinker indicator light cross circuits to the high beam indicator light at this connector.

In your case you may find that the connector light power socket is not well connected to the corresponding circuit board pin....the easiest thing to do RHRN is to get some slack in the harness to allow the circuit board connector to be firmly pressed all the way into place so there is no gap.

The best thing is to pull the circuit board connector off & clean all of the sockets & pins then test the light power socket on the circuit board connector for power with the lights on.

I can give you an electrical diagram for a 65 Dart that identifies which socket(of the 9 sockets) of the connector should carry the power for the instrument lights if you don't have a circuit diagram for your car. Then you can check for power at that socket with the lights on. If you have power there then you know there is a high probability the circuit board or connector is the location to focus your attention.

If your really in a hurry try jiggling the circuit board connector with the lights on.....if the instrument lights flicker on & off you got a high probability the connector is the culprit.

Let me know if you want a 65 Dart picture of the connector & which socket carries the instrument light power...it would be best if someone posted your Valiant connector & identified the light power source socket.