Bulb with black plastic wire

[asjt3]

Folks, on the back of the instrument cluster there’s a bulb with what seems to be a black solid plastic stiff wire attached. It’s black with a green stripe, anybody know what this is for? Doesn’t seem to be electrical in nature?

1990 chev suburban V1500

 

[dd1990]

That wire is a fiber optic line, sends light from bulb on dash cluster to the ash tray

 

[Turbo4whl]

If it is on the right side of the instrument cluster, it is fiber optic line to light up the ashtray. On the left side it lights up the wiper switch (older model than the '90)

Early squares had a fiber optic ribbon to light up the wiper switch.

 

[Turbo4whl]

That wire is a fiber optic line, sends light from bulb on dash cluster to the ash tray

I was slow to respond, David has it ^^^

 

[asjt3]

Wow that’s interesting thanks for the replies. Now I’m confused though, because there is also a free hanging bulb that I thought plugs into the ashtray like on the GMT400s. Is it possible this dash cluster is from another year or is the free hanging bulb for something else?

 

[gmbellew]

Wow that’s interesting thanks for the replies. Now I’m confused though, because there is also a free hanging bulb that I thought plugs into the ashtray like on the GMT400s. Is it possible this dash cluster is from another year or is the free hanging bulb for something else?

might be for the HVAC controls if it has a bulb attached and doesn't have a spot in the cluster.

 

[asjt3]

I found where the fiber line plugs in above the ashtray. Very interesting. I’ll have to figure out whether this bulb plugs into the HVAC cluster.

 

[PrairieDrifter]

I found where the fiber line plugs in above the ashtray. Very interesting. I’ll have to figure out whether this bulb plugs into the HVAC cluster.

It goes into the very top far right of the gauge cluster.