dash lightning

[August]

Hello,

I was working today on my truck changing some dash bulbs. My truck is a 1980 GMC Jimmy. My truck has factory tach, and there is an optical wire that goes from the dash bulb to somewhere? The a/c panel and the radio had their own bulbs, so this optical wire must lighten something

Thanks,
Augusto from Spain

 

[pauly383]

Window wiper/washer switch .

 

[73k5blazer]

There were optical wires that go to the wiper/washer switch and/or the ashtray, depends on year. My 86 has column wiper switch, optical wire goes to above the ashtray.

 

[neverendingproject]

There were optical wires that go to the wiper/washer switch and/or the ashtray, depends on year. My 86 has column wiper switch, optical wire goes to above the ashtray.

Same here.

 

[August]

Just checked on truck, the washer/wiper switch has its own bulb.

My truck is a 1980 model, are the ashtrays lighted? The optical wire are not very long, so I supposed it must go somewhere between the radio and climate cluster. I could not get this info on the shop manual.

Another question (sorry ) when I pulled the dash cluster I noticed there is a "choke" red light indicator but there was no bulb into. It must be? The engine is a 350 4bbl.

 

[73k5blazer]

Those are even more variable. THey are called "Tell-Tale" indicators. THey vary year-to-year, engine-to-engine, and various options. My '86 has an no-bulb choke indicator as well. Those plastic overlays they use for those come in double and singles, it's the doubles they used sometimes on various vehicles with one side being unlit, they were just after saving money and using the wording on the 'other' side. The service manuals, even from GM, won't call out which ones ar esupposed to be there and not.
Usally, a good indicator is to follow the trace on the printed circuit and see if there's a wire connected to it. One side of the bulb will be common ground with almost every other buld and gauage on there, the other should be by itself and go the connector body, see if ther's a mating wire to it, if there is, it's suposed to be lit.