[Question] How to fix very dim dash lights?

[D3X]

Vehicle: 91 Merc GM GS

I think I have came to the right place to obtain an answer to this question.

My dash lights (speedo mainly) are extremely dim and not visible when driving in normal conditions.
I can see them just barely if I turn the brights on at night.
As far as I know, all of the notification lights on the cluster work fine, just not the lights that light up the actually speedometer.
I have note had the car long.

Would this by due just very old bulbs? A circuit? A short?
Help if very much appreciated!

[79lincolnlover]

Turning the headlight knob should increase the brightness. Bulbs are probably old.

[mcninetyone]

If turning the headlight knob doesn't work, you probably need a new headlight switch.
And replacing the bulbs wouldn't hurt, but thats not your problem.

[gadget73]

possible you've got a bulb or two out. if the lamps in the climate control look normal, my bet is on a dead bulb in the cluster. I don't remember how many there are on those, but there aren't very many. One being out would make the whole works noticeably dim.

[D3X]

Turning the headlight knob should increase the brightness. Bulbs are probably old.

Wow, I didn't even know the headlight knob rotated.
This solved my issue.
So much simpler than I would expect, ha!

This forum is truly a fountain of information that is very helpful.
Thank you all for the help!

If turning the headlight knob doesn't work, you probably need a new headlight switch.
And replacing the bulbs wouldn't hurt, but thats not your problem.

Rotating the headlight knob did work, I will still be replacing the bulbs.
They definitely need it.

possible you've got a bulb or two out. if the lamps in the climate control look normal, my bet is on a dead bulb in the cluster. I don't remember how many there are on those, but there aren't very many. One being out would make the whole works noticeably dim.

I will be replacing the bulbs this weekend. I'll post back with the quantity of bulbs within the cluster then.

[gadget73]

I think its 2 or 4 for illumination, but I really don't remember for sure. A bunch of those bulbs are for various warning indicators. Honestly they don't really get dimmer with age, and they don't go bad that often. More frequently its bad connections to that foil trace they contact that causes issues. I've fixed a lot of "burned out" light bulbs with a pencil eraser and gentle bending of the brass contacts on the bulb holder.

[slack]

I just so happened to have a speedo from an '87 CV on my desk here at work so I snapped a pic.

It looks like 4 bulbs for illumination. 2 on the bottom and 2 on the top. (Sorry for the crappy cell phone pic)

[Djtb78]

You could also replace them with l e d 's! Much brighter

[87gtVIC]

87 and 91 speedometers are entirely different.

[slack]

Ah crap. You're right. Sorry about that. I missed the year when I first read through.