'51 300 Instrument Cluster Lights

Posted by Dave Merrick On 2010/11/14 15:48:46

Well, I did end up pulling the speedometer out of the 300 cluster. I'm glad I did. It gave me a chance to lube all the gears and mechanisms inside.

But "While I'm in there" there is another issue I'd like to address; that of dim instrument cluster illumination.
I have replaced all the bulbs with the correct type, cleaned the dimmer rheostat, and still the lights are dim. Now that I have access inside I have a few questions about whether or not what I have is normal.

Inside the cluster the back-side of the chassis is bare metal, and the front is painted black. The strange part is the back is dirty/rusty and the front looks brand spanking new. This leads me to wonder if the front of the cluster chassis was painted black by a previous owner and is not reflecting enough light into the gauge glass.

Also, the bulbs have metal "reflectors" (for lack of a proper term) that surround the bulbs, boxing them in and only allowing light out the top.

From a Google search on this topic, a guy said that Studebakers had black-light filters over the bulbs and he thought Packards might have them also. Which kind-of makes sense as the gear shift indicator is this sort of arrangement on my 300.

So the question is. What's supposed to be in there and how's it all supposed to work?

Thanks Again!