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No Dash Lights. Where to start troubleshooting?

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Old 11-06-2010, 05:21 PM
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PUNISHER VETTE
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Default No Dash Lights. Where to start troubleshooting?

I've had no dash lights since owning the car. I'm going to have the interior torn apart while doing carpet so i want to fix/upgrade the lights while i'm there.

I have warning lights (parking BRAKE, Brights, turn signals, seat belt...)

But nothing lighting the gauges.
I'll be checking the fuse first(even though i'm sure i've checked it before)
From there I'll be checking to see if all the bulbs are just burnt out?
then either trace back power or check ground?

I have a wiring diagram so that'll help the process, just didn't know what you all suggested first that could help me out.
Old 11-06-2010, 05:56 PM
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joewill
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turn signals work? high beam indicator work? console gauges light up or just only the dash lights not work?
Old 11-06-2010, 05:59 PM
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kmobrien76
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I'm in the same boat, had old co-worker install a "dukes of hazzard dixie horn" drove home then no dash lights, gotta check the fuse when I get around to it, been over a year, hahaa

Like yours though, my turn signal indicators, parking brake light, etc light up just not the dash or gauges..

Kevin
Old 11-06-2010, 07:03 PM
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PUNISHER VETTE
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Originally Posted by joewill
turn signals work? high beam indicator work? console gauges light up or just only the dash lights not work?
all light up lights aren't working. Console gauge cluster, spedo/tach...

courtesy lights work though.
Old 11-06-2010, 07:06 PM
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SanDiegoPaul
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First place to look is the headlight switch. It has a rheostat around it to control the brightness of the dash. Check for an open in the rheostat. Courtesy lights are not on this circuit.
Old 11-06-2010, 07:27 PM
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...Roger...
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Check the right side fuse holder for power when the headlight switch is pulled out and rotated.
Old 11-06-2010, 07:39 PM
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Originally Posted by SanDiegoPaul
First place to look is the headlight switch. It has a rheostat around it to control the brightness of the dash. Check for an open in the rheostat. Courtesy lights are not on this circuit.
Here is where to start, one of the easiest check you have
Old 11-06-2010, 07:51 PM
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Originally Posted by Ironcross
Here is where to start, one of the easiest check you have
Pulling the dash down to get at the headlights switch is easier than checking the power coming "from" the headlight switch at the fuse holder ?
Old 11-06-2010, 09:01 PM
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well I'm not sure if this will work or not but the car was missing 1 fuse that said

INST LPS, The 5amp one.

I'm assuming it means Instrument something???

I broke the 10amp gauges one getting it out to check so i went and bought an assortment pack from autozone and we'll see if just adding the 5amp fixes it?

This would probably under the idiot should have checked before he asked online department...

Old 11-06-2010, 09:08 PM
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Thats your dash lights fuse !
Old 11-06-2010, 09:46 PM
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well it still didn't work even after I put the 5amp AGA fuse in there....

So tomorrow i guess i'll have to open up the dash a bit more and start trouble shooting...

I'm guessing there wasn't a fuse in there because someone was trying to figure this problem out before me....
Old 11-06-2010, 10:18 PM
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7T1vette
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No fuse in that spot tells me something, right there. Someone pulled it out and probably because of a known problem or because they just didn't work. My best guess was that it just kept blowing fuses, so they were afraid there was a 'dead short' which could start a fire in the dash area if current kept flowing into that circuit for too long. If you check that 5 a. fuse again, I'm betting it is already fried.
Old 11-06-2010, 10:59 PM
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Originally Posted by 7T1vette
No fuse in that spot tells me something, right there. Someone pulled it out and probably because of a known problem or because they just didn't work. My best guess was that it just kept blowing fuses, so they were afraid there was a 'dead short' which could start a fire in the dash area if current kept flowing into that circuit for too long. If you check that 5 a. fuse again, I'm betting it is already fried.
Just went out and pulled the fuse and sure enough it was blown already.

That narrows it down some but where should I start to look for this short when I get the panels off tomorrow?

From my wiring diagram it looks like the same wire comes off that fuse, splits and goes to each of the light bulbs. On the other side of the fuse it goes to the light switch...
Old 11-06-2010, 11:13 PM
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kmobrien76
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Not to sound dumb but where do I check my dash light fuse? Is it under the right side dash?

THanks,

kevin
Old 11-07-2010, 06:28 AM
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...Roger...
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Originally Posted by PUNISHER VETTE
From my wiring diagram it looks like the same wire comes off that fuse, splits and goes to each of the light bulbs. On the other side of the fuse it goes to the light switch...
That is correct ,
(NO reason to go towards the HL switch -drop the steering column-lower the left side dash and so on-thats a waste of time !)
you need to go the opposite direction.
In your diagram you should notice the left side of the fuse holder is the Gray wire side of the circuit. Your correct this wire splits and goes several directions to the dash illumination bulbs. Look for a pinched gray wire. One very common thing you'll find on these old cars is the socket falls apart and the gray wire then comes in contact with the metal housing.
I start off with the easiest , looking up from the bottom of the dash,
then I remove the right side of the dash and look in behind the center cluster and so on until you find the short.
Old 11-07-2010, 06:32 AM
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Originally Posted by kmobrien76
Not to sound dumb but where do I check my dash light fuse? Is it under the right side dash?

THanks,

kevin
Left side....(if you have a 4 speed the clutch pedal foot almost hits the fuse box on every shift)
Old 11-07-2010, 09:19 AM
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I believe back in the day they used to locate shorts with the good ole paper clip method, ummmm...... I would stick with Rogers advice 1st though ! Good luck, dont ya just love those electrical gremlins.

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To No Dash Lights. Where to start troubleshooting?

Old 11-07-2010, 10:46 AM
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Remove the positive battery lead. Then use an ohmeter to test the output side of the fuse clips to see if you have a dead short to ground. Repeat the process for the fuse clip on the other side [fuse out of the clips, of course]. One side or the other should show a short condition (zero ohms).

Note: I would expect to see low ohms on the output side, as you could be checking continuity through a light bulb, etc. That would get you into the range of a few ohms. But your problem is [essentially] a 'dead' short and that's what you need to look for. Short both meter leads to ground and see where the meter needle (or reading) ends up...that's what you should see when you find your problem.

Once you find the short, you need to move 'away' from the fuse but in that electrical 'line' until you find that the short condition disappears. The short will then be located somewhere between the side of the fuse showing the short condition and the point at which the short disappears. You just need to continue to narrow the search area in that 'bad' section until you isolate the short. Good luck.
Old 11-07-2010, 03:10 PM
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Well I got the center console and gauge cluster out today along with all the carpet.

Next free day I have I'll most likely tackle the the steering column and speedo/tach dash pad to open up all that area.

This should allow me view of the entire area that is having a problem. From what I could see in the console and gauge cluster area the lighting looked pretty good at all points. So i'm guessing my problem lies somewhere over in the tach/speedo area.
Old 11-08-2010, 01:53 PM
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The instrument lamps have to be grounded or they will not work. They ground by clipping into the rears of the metal cased instruments and by the harness ground on the driver's door hinge post up under the console.

If you keep blowing IP fuses, I'm betting the headlight switch has a bad rheostat.



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