Help! dash lights in a 1980 vette

[benj9002]

my dash lights on the speedo and gauages are out, but all the gauges work besides the speedo and the clock and the turn signal indicators work, ciggerette lighter works and curtosy lights work. Will the printed circuit on the gagues fix this I hear it controls the dash lights?

 

[Chrisr]

This happened to me back in the day when I had my 80. Check the fuse first. That was the problem with mine, I think. It was back in 82 or 83 when it happened to me, so my memory might be foggy. I do remember though, it was nothing like a circuit board, just a simple fix. Thats why I'm saying the fuse.

Good luck and keep us posted.

 

[benj9002]

Sorry should have said I checked the fuses but no luck?

 

[73shark]

Need to start tracing down where you are losing the 12V. Could be the headlite switch or a disconnected/broken wire. Probably need to get a factory shop manual for the wiring diagrams.

 

[Rebelrob]

I am new C3 owner so I dont have much to offer. But I will say that the dash lights on my 82 are not very bright. Even with the know cranked all the way up. It has to be almost completely dark before you can see them.
Im sure you have checked this, but try turning the headlight know back n forth to ensure you have them turned up.

 

[73shark]

I am new C3 owner so I dont have much to offer. But I will say that the dash lights on my 82 are not very bright. Even with the know cranked all the way up. It has to be almost completely dark before you can see them.
Im sure you have checked this, but try turning the headlight know back n forth to ensure you have them turned up.

Try jumpering 12V directly to the lite circuit which will bypass the rheostat on the headlite switch and see if they're any brighter. If so, then probably need to replace switch.

 

[Rebelrob]

Where is the light circuit located?
In the fuse panel area? or is it by the light switch?

Try jumpering 12V directly to the lite circuit which will bypass the rheostat on the headlite switch and see if they're any brighter. If so, then probably need to replace switch.

 

[73shark]

Really need a factory shop manual to trace this down.

 

[Rebelrob]

Be nice to see a pic of somebodys dash lights at night, without a flash of course just so I am not imaging that mine lights seem dim to me. Even when they are turned all the way up.

 

[Mr. Chuck]

The brightness of the lamps is a product of the current / voltage seen across the lamp; as the circuit connections age, resistance developes at the various connectors. as well in the light switch rheostat, even the lamps brightness get weak with time, especially if prior owner had them set very bright routinely. I would try removing and reseating each connector, this may help in wiping away the dirt / oxidation that builds over time and reduce the resistance along the light circuit path, resulting in an increase in dash light brghtness. Hope this helps, having a shop manual aids in locating the circuit path.

 

[Rebelrob]

I see. The connector , you mean the actual light bulb connector? I do not know what the inside or backside of these guages look like. Im thinking they all each have their own little lite bulb. Wonder if the bulbs can be replaced easily, common auto part store or if they are special order.
Thanks for the insight.

R

 

[Mr. Chuck]

I would start with the larger, multi-contact connectors, like the one on the light switch and the plugs on the rear of the instrument panel. My 81 instrument panel has a flexible mylar sheet with the varies circuit paths to the panel components, like the lamps which have plastic base protrouding out the rear, these you twist (gently) CCW ~ 1/4 of a turn to remove. Lamps that are near end of life are blacken from years of high heat. Replace these at minimum, there are some opinions that replacing all will insure equal brightness. Also look for dirty or damaged contacts / circuitry around lamp mtg holes. Dirty / tarnished copper can be cleaned by using a soft rubber erasier (like the kind on the end of a lead pencil), take care to rub very gently, just enough to brighten the contact surface. These are very thin and birttle from age and crack very easly.
I hope this isn't too much detail and makes sense. Caution; A word to the wise, when removing, disconnecting anything take pictures, make written notes, etc. It will help to minimize many problems, delays in re-assembly, new problems, etc' I have found a digital camera envaluable in documenting this aspect of the job.
Good trouble shooting!!

 

[Rebelrob]

OK. Thanks. I have a shop manual on order. So maybe this will all make a little more sense when it arrives. I was going to try the bypass 12v tip you mentioned earlier and then go from there. But as you say, its probably all old and dirty back there.
Thx again and I will let ya know what I discover.
R

I would start with the larger, multi-contact connectors, like the one on the light switch and the plugs on the rear of the instrument panel. My 81 instrument panel has a flexible mylar sheet with the varies circuit paths to the panel components, like the lamps which have plastic base protrouding out the rear, these you twist (gently) CCW ~ 1/4 of a turn to remove. Lamps that are near end of life are blacken from years of high heat. Replace these at minimum, there are some opinions that replacing all will insure equal brightness. Also look for dirty or damaged contacts / circuitry around lamp mtg holes. Dirty / tarnished copper can be cleaned by using a soft rubber erasier (like the kind on the end of a lead pencil), take care to rub very gently, just enough to brighten the contact surface. These are very thin and birttle from age and crack very easly.
I hope this isn't too much detail and makes sense. Caution; A word to the wise, when removing, disconnecting anything take pictures, make written notes, etc. It will help to minimize many problems, delays in re-assembly, new problems, etc' I have found a digital camera envaluable in documenting this aspect of the job.
Good trouble shooting!!