InstInstrument Panel Wiring Question, What is This?

[Ironangel]

Ok, I replaced the old dash "after" removing the instrument panel,radio,ash tray,defroster vents and glove box lid. I damaged the glove box liner removing it. There is single wire leading to a single twist in bulb/socket. All the other twist in single unit bulbs are energized off the circuit board/sheet. The bulb socket in question was white instead of black like the others. It also had "Strange" steel clip molded into the top of the twist in socket. What is this and why is it engineered like that? I busted it also removing it from the panel. One more question, Is one bulb socket opening supposed to open on the back of the gauge cluster? I can see "TEMP" inside the bulb opening. My truck has a mechanical temperature gauge, so does the factory skip that bulb or is it missing? Heres some pics and Thanks for the help you guys!

[Livrat]

That wire is actually a fiber optics cable designed to transfer light from the bulb to your shift indication on your steering column.. normally all the light sockets are filled even though your temp gauge is mech..

[eightbanger]

Originally Posted by Livrat

That wire is actually a fiber optics cable designed to transfer light from the bulb to your shift indication on your steering column.. normally all the light sockets are filled even though your temp gauge is mech..

That bulb isn't for the shift indicator it's way to big, the bulb in the shift indicator is tiny and has it's own built in housing in the column, it also has nothing to do with your dash as you can see yourself it does not match, the only things I can suggest is that it maybe the light to illuminate your heater control panel or it was some PO add on/mod that is no longer in use. Where is your glove box light by the way? the bulb in the pic does not match that either but could be some sort of PO modified version of a glove box light...just guessing.

[sjarrett71]

Livrat is correct. That light with the fiber optic cable gets plugged into your dash and the cable provides the light to your gear indicator on a non-tilt column.

Eightbanger is correct too although he is talking about a tilt column.

[70shortfleet]

Originally Posted by Livrat

That wire is actually a fiber optics cable designed to transfer light from the bulb to your shift indication on your steering column.. normally all the light sockets are filled even though your temp gauge is mech..

Livrat is correct, it is a fiber optic cable to send light to shift indicator on non tilt automatic columns. It take the light from that bulb which should be on when light are turned on.

[BLACK AND BLUE 67-72]

Livrat is correct, that is for the indicator on a non tilt column, tilt has a wire that plugs into the fuse box and has its own bulb in the column.

[eightbanger]

Originally Posted by sjarrett71

Livrat is correct. That light with the fiber optic cable gets plugged into your dash and the cable provides the light to your gear indicator on a non-tilt column.

Eightbanger is correct too although he is talking about a tilt column.

I see!! I have been edumacated, I really should stop jumping in and assuming every Truck is the same as mine

[Ironangel]

Thanks for the replies you guy's! Ive reattached the metal clip that (I broke off removing) holds the fiber optic cable and will perform some lighting tests to see if it still works. I would have never guessed that "fiber optics" was engineered into these "old girls!" My truck, a 72 Custom didnt come with a tilt wheel or a lighted glove box. It does have the bulb receptacle for the heater control. Thanks again! PS. I just tried uploading some pics with the dash painted all black, but for some reason its not uploading...?

[70shortfleet]

Originally Posted by Ironangel

Thanks for the replies you guy's! Ive reattached the metal clip that (I broke off removing) holds the fiber optic cable and will perform some lighting tests to see if it still works. I would have never guessed that "fiber optics" was engineered into these "old girls!" My truck, a 72 Custom didnt come with a tilt wheel or a lighted glove box. It does have the bulb receptacle for the heater control. Thanks again! PS. I just tried uploading some pics with the dash painted all black, but for some reason its not uploading...?

Late 60's early 70's Corvettes also used fiber optic cables in some of there dash-console lighting