Tricks for Rallye dash lights

[6PKRTSE]

None of my Rallye dash lights work for my instrument panel gauges. I replaced all of the bulbs with the correct new bulbs in the light bar and still nothing. Any tips or tricks on where to start from there?

 

[tonysrt]

Start with the dimmer switch. Being some 50 years old they are junk to begin with. The thin wiper arm breaks off and that is usually the problem with it.

 

[Challenger RTA]

Grounds Dash lights a Brighter possibility