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Old 12-17-2018, 09:27 PM   #1
BigRandy
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Dim Dash Lights

The instrument lights work on my 74 C10 but they are dim and I'm guessing this is not uncommon with a 45 year old truck.

Is there a fairly common fix for this. Maybe a grounding problem or a different bulb that would work?

Thanks
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Old 12-17-2018, 09:45 PM   #2
Getter-Done
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Re: Dim Dash Lights

Try twisting the headlight knob right to left
with the dash lights on and see if they flicker
or get brighter / dimmer.
The coils in the (Example picture ) below may have corrosion on them.
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Old 12-17-2018, 10:54 PM   #3
BigRandy
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Re: Dim Dash Lights

Quote:
Originally Posted by Getter-Done View Post
Try twisting the headlight knob right to left
with the dash lights on and see if they flicker
or get brighter / dimmer.
The coils in the (Example picture ) below may have corrosion on them.
Attachment 1848369
It's been like this during the year that I've owned it and I've never had a flicker, but to CMA and rule out something obvious I pulled the switch a few months ago and sprayed it with some CRC and cleaned the connector. No change. Turning the switch just makes it go from dim to dark.

I should have checked voltage at the sockets when I had the panel open but I didn't. It's not a big deal to pull it again but before I do that I'm hoping to find some common fix that maybe everyone but me has heard of. Considering the age of these square bodies the problem could be almost anything.

I suspect a dirty or corroded ground but I don't know where it could be. I pulled and cleaned the ground on the firewall and have no other electrical gremlins that I am aware of. The battery and alternator were replaced this summer and the truck can sit for days and still spin like a top when I turn the key.

I'm not completely stumped but I am stuck at the moment.

Thanks for the reply
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Old 12-17-2018, 11:19 PM   #4
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Re: Dim Dash Lights

In one of my 78 Chevy trucks I owned.
I put the orange covers over the bulbs.
Maybe the bulbs are ???
Maybe a bulb change like you said in your
first post may be a good next step.
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Old 12-18-2018, 02:34 AM   #5
BigRandy
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Re: Dim Dash Lights

Quote:
Originally Posted by Getter-Done View Post
In one of my 78 Chevy trucks I owned.
I put the orange covers over the bulbs.
Maybe the bulbs are ???
Maybe a bulb change like you said in your
first post may be a good next step.
They are not colored. I checked. I'm going to see if anyone makes an LED equivalent as a direct replacement. Will also check the voltage. Even though it has the original (AFIK) incandescent bulbs the cluster should be brighter than it is.

I've had square body trucks before and I'd say these are about half as bright.
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Old 12-18-2018, 08:00 AM   #6
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Re: Dim Dash Lights

Check the voltage between the leads for the lights. Using the same ground that the lights use. Thinking you might have a bad ground given that you get a full 12v out of the headlight switch.

If you do go LED, be aware of light temperature (color). Incandescents are usually around 2700-4000k and give off a more yellowish light. White LEDs will go up to 6500K. These are the really bright white lights. The color may look odd in the old dash.
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Old 12-18-2018, 12:52 PM   #7
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Re: Dim Dash Lights

I found that my 85 cluster was completely dirty inside. Years of dust had settled on the bulbs and housing. (the housing is what reflects the light back out towards the gauge and gives it that Greenish tint)

I broke mine down and washed the housing then gave it a good respray with some flat white. Then replaced all the bulbs with new ones. (double check they are all working, mine tend to be flaky) It's not the brightest but much better than before.
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Old 12-19-2018, 01:04 PM   #8
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Re: Dim Dash Lights

This will get you started but remember that LED bulbs are polarity sensative and most of them are not dimmable so you won't want those or you may be getting tired of the glare after awhile.

http://67-72chevytrucks.com/vboard/s...archid=6255836
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