'Odd' gauge bulb socket

[K20Detroit]

I have a white bulb socket, with some sort of fairly thick wire on it.
On my truck, it is set up in the far right gas gauge position.
On a spare cluster I picked up, it was over beside the speedo.
My trucks cluster area was torn apart and put together wrong by the previous owner, the gas gauge may not be where it originally was.
The spare, same idea.
Any idea what it is about? The bulb works.
Does it have anything to do with cruise? The previous owner removed the cruise on my cluster.

[jrbarrie83]

That "wire" is a fiber optic line going to light the ash tray. GM was super excited about fiber optics in the 80's. Seems like they were looking for any excuse to put it in every vehicle, even in the most random places.

I'm not exactly an expert, and I'm sure this forum will be a great resource with many more knowledgeable folks, but if you have specific questions, I'd be happy to help. I've had to scrounge the salvage yard for parts for both my 83 chevy and 86 olds. Lots of pieces missing or systems incomplete on both when I got them.

[K20Detroit]

So to get this straight; it's a fiber optic line that uses the dash bulb as a light source?
That sound's rather unique. I've worked with fiber optic before for internet, though not lighting.
I noticed the other end heading towards the ash tray, though didn't think much of it.
I'm fairly knowledgable on the trucks, though there are odds and ends that I come across and don't know about.
I can say that it has been a nightmare finding parts for my '84. I've been to a dozen yards within several hours. Due to how many options my truck has, it's hard finding the right parts. Some parts I need aren't being reproduced, so that's not an option.

[jrbarrie83]

Yeah I hear that. I just went to the big yard near me today and came back with nothing. Only had a half dozen trucks and they were all pretty much picked over. Didn't even see any g-body cars like mine and they used to have dozens. I think the days of these vehicles coming off the road regularly are over - which is a good thing overall, but bad for us.

As for the light, yes it is just taking the light from the bulb in the dash to light the ash tray. My olds has the fiber optic light monitoring system, but also has a single light in a pod dedicated to nothing but making a little blue square next to the headlight switch light up. It's buried so deep in the dash it is nearly impossible to replace. They could've actually lit the switch, but instead went this route. Seems like they were looking for any excuse to use fiber optics. It certainly is unique though.

[blazer74]

73 74 use the fiber optic for the wiper switch. It's riveted to the dash. So if you don't unplug the bulb from the cluster you will damage the tape if you pull on it.