Headlight switch fibre optic? 86 Salon

[mr evil]

So, I noticed that attached to the rear of the headlight switch there seems to be a fibre optic line? I traced this back to a bulb housing about 6" behind the dash. The bulb inside the housing is a strange one that I've never seen before. It looks like a 161/168/194 but it has GE 550 (i think) stamped on it and the top of it looks like a thicker glass, almost like a magnifying glass.
1) Does anyone know what this does? It appears to attach behind a tiny blue lense on the left side of the switch plate. I figure it's some sort of indicator to find the switch in the dark, but I don't think I've ever seen one working before?

2) Is this bulb readily available anywhere? I know I couldn't find it in the automotive bulb section at Can. Tire.

Edit: I think it's a GE 558 rather than 550 and they seem to be available online, but I still don't know what it's supposed to do or if it's worth ordering :?

 

[86Cutlass383SR]

I've wondered the same thing. Is this tied in with the fibre optics option or is it a seperate fibre oprtic for just the headlight switch.

 

[mr evil]

Well, I don't have any of the other FO options, so I'm thinking it's common, but maybe not working in most cars anymore?

 

[username]

Its funny you mentioned this as I just pull my dash out today and noticed this.I was also wondering what appears to be an Infra-red reader pointed to the back of the mechanical speedo ties into also?

 

[High Roller]

I found that Optical Dash Bulb on my 86 442 couple years ago, it was GE558. But i just installed a 194 bulb. neat little blue light. Later found it at local Grainger #3JK80 $2.08

 

[86Cutlass383SR]

I was also wondering what appears to be an Infra-red reader pointed to the back of the mechanical speedo ties into also?

This would be the VSS (speed sendor) for the ECM.

I found that Optical Dash Bulb on my 86 442 couple years ago, it was GE558. But i just installed a 194 bulb. neat little blue light. Later found it at local Grainger #3JK80 $2.08

Did you happen to notice what looked to be burn marks on the gray plastic bulb holder? The original bulb gets too hot and burns the holder. I remember reading years ago that some guys replace them with a differant bulb, probably the 194. Slightly less illumination but longer bulb life too.

 

[mr evil]

I found that Optical Dash Bulb on my 86 442 couple years ago, it was GE558. But i just installed a 194 bulb. neat little blue light. Later found it at local Grainger #3JK80 $2.08

Lol! Neat little blue light? That's all we get? Then I guess I'll just replace it with a 194 as well and be done with it.

On a related note, I believe fully 2/3 of the bulbs were burnt out in my car so I just replaced them all save for a couple.

I have a console car and didn't buy a bulb for the ashtray as this car doesn't have the under-dash ashtray. As I was replacing bulbs, I noticed the under-dash bulb IS in the car though, just hanging there. I'm a bit perplexed, is that supposed to be somewhere? Used for something else? Anybody know?

I think I am missing a part of my glove box lighting. Does anyone have a pic handy of what is supposed to be there for lighting?