Question about grounds for the digital dash
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Melting Slicks
Joined: Jun 2004
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Question about grounds for the digital dash
Could anyone give me a good description, or maybe even a picture, of the locations of the 2 grounds for the digital dash in an '85 Vette? All i can find seem to be really vague. I read that there are two grounds for the Digital Dash cluster, one in the engine compartment behind the valve covers, and the other inside somewhere. I think the ground inside is giving me problems. Can anyone help? 
Melting Slicks
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From: What did the 5 fingers say to the face? SLAP!!
Re: Question about grounds for the digital dash (mikey whipreck)
The second ground is supposed to attach somewhere on the drivers side door pillar, beneath dash level.
I know it's vague, but Killebrews book doesn't have a diagram for this. Just the description above.
[Modified by flyersfan1088, 6:43 PM 6/24/2004]
I know it's vague, but Killebrews book doesn't have a diagram for this. Just the description above.
[Modified by flyersfan1088, 6:43 PM 6/24/2004]
Melting Slicks
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From: What did the 5 fingers say to the face? SLAP!!
Re: Question about grounds for the digital dash (mikey whipreck)
1984-1989 Corvette Digital Cluster - A Complete Step-By-Step Operational And Troubleshooting Guide
by Gordon Killebrew
Ecklers or MAD carry it in their catalogs
by Gordon Killebrew
Ecklers or MAD carry it in their catalogs
Drifting
Joined: May 1999
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From: Sacramento, CA Money can't buy happiness - but it's more comfortable to cry in a Corvette than a Yugo.
Re: Question about grounds for the digital dash (mikey whipreck)
mikey, Can you post a pic of the actual location on your vette? It will help others in the future so they don't have to guess based upon the description. I have Gordon's book too (EXCELLENT), but adding a pic always helps.
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Melting Slicks
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Re: Question about grounds for the digital dash (Mike_88Z51)
That ground is for the telltale indicators (i.e. idiot lights). There is only one black ground wire in that area, its at the spot where the plastic door sill ends, and the rubber molding starts. You can see the wire without taking anything off, just pull the carpet back slightly, and you'll see a single black wire coming down. (I actually got a mirror to look behind the plastic to make sure it was the right ground before i started taking stuff apart). Sorry, i couldn't post a picture, I had the whole thing backtogether before i read your post... maybe i can take one of the wire going in to give people an idea.
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Burning Brakes
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From: Cape Cod Ma
Re: Question about grounds for the digital dash (mikey whipreck)
I had the same problem as you. The fix was the grounds to the backside of the drivers side sylinder head. Very hard to get at ( I did cleaned them up when the engine was apart) and everything worked great. The dash used to flicker/ go dim untill I played with the grounds on the head.
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Melting Slicks
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Re: Question about grounds for the digital dash (redfast)
Did your turn signals and high beam indicator come on bright when your dash went dim? And is it possible to describe the location of that a little more? is it just a regular black ground wire?
Le Mans Master
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From: seattle WA
Re: Question about grounds for the digital dash (mikey whipreck)
According to Gordon when the dash lights are inoperative and the HIGH BEAM AND DIRECTIONAL INDICATORS COME ON DIM ,look for a bad ground. Yours seem to be the opposite, although it's still probably a bad ground. Did you do the ground thing to the ambient sensor?The black/white wire is the same one coming from cavity D3 (the ground wire) the ground going to the engine block-drivers side should be a black/white wire, and yes it's hard to get to-but if you splice into the black/white wire on the ambient sensor, you can run it through the fire wall and ground it easier by the battery on the frame-there's already a black ground to the frame there and you can simply attach it there, rather than the block. 
[Modified by rick lambert, 3:10 AM 6/27/2004]
[Modified by rick lambert, 3:10 AM 6/27/2004]
Thread Starter
Melting Slicks
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Re: Question about grounds for the digital dash (rick lambert)
Tommorrow morning (when i'll be able to see what im doing a little better), i'll search for that ambient ground. In the meantime i have the cluster apart and i'm double checking all my soldering and making sure stuff is clean. None of the info shows in the 3 lcd's. My indicators work right. What stumps me is that the cluster works perfectly once in a while (VERY rarely). Im not sure if thats a sign of a bad ground or a bad connection in the cluster. Im gonna try and get a picture of that ambient ground for everyone. Im sure im not the only one whose messed with it
Le Mans Master
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From: seattle WA
Re: Question about grounds for the digital dash (mikey whipreck)
First, as long as you have it out, when they (corvette parts service co.) refurbishes the clusters they piggy back a wire between the two ground terminal on the cluster-sorta insurance. Second-the ambient sensor-attached to the interior bulkhead connector is almost impossible to miss-it's about the size of a dime, 1/2 inch thick with two terminals-you splice into the black/white wire (which is one of the ground wires for the cluster cavity D3) and run it to a ground.
[Modified by rick lambert, 5:32 AM 6/27/2004]
[Modified by rick lambert, 5:32 AM 6/27/2004]
Thread Starter
Melting Slicks
Joined: Jun 2004
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Re: Question about grounds for the digital dash (rick lambert)
First, as long as you have it out, when they (corvette parts service co.) refurbishes the clusters they piggy back a wire between the two ground terminal on the cluster-sorta insurance.
[Modified by rick lambert, 5:32 AM 6/27/2004]
[Modified by rick lambert, 5:32 AM 6/27/2004]
Racer
Joined: Apr 2004
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From: Farmington Hills MI
Re: Question about grounds for the digital dash (mikey whipreck)
Here is a link to a tech article on the digital dash. Looks like an excerpt from Gordon Killebrew's book. It shows a picture of the ambient temp sensor as well as the wiring connector at the side of the instrument cluster. I recently used this article (as well as another one I found on this site) to repair my dash. You will need to remove the lower sound panel in order to get at the ambient temp sensor. once you do, it is located on the left side of the firewall (bulkhead). I spliced into the ground wire and ran a new ground wire through the firewall and tapped it into the front frame rail. I also resoldered te ground pin on the circuit board. It works fine now. Very rewarding repair, and not too difficult using the instructions.
http://www.corvettemagazine.com/1999...ash/dashp1.asp
http://www.corvettemagazine.com/1999...ash/dashp1.asp
Thread Starter
Melting Slicks
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Re: Question about grounds for the digital dash (TaylorMutts)
Thanks for your help guys. I'm gonna get to that ambient sensor ground, and clean that. If the dash still doesnt work, I'll get a replacement on ebay or send it away for repair. At least i'll know i've tried everything i can.
Melting Slicks
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From: What did the 5 fingers say to the face? SLAP!!
Re: Question about grounds for the digital dash (mikey whipreck)
I'm having a weird problem with my dash now. Everything is dim but the turn signal indicators are NOT on. Everyonce in awhile, usually when the car has been sitting outside with windows up on a hot day(very hot inside car) the Tach side will illuminate, but not the rest of the dash. I know it's a bad connection or ground, I just don't feel like pulling the dash out and cleaning the connection between the 2 boards. Does this sound like the plug in connectors, or the connection between the 2 circuit boards?
Racer
Joined: Apr 2004
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From: Farmington Hills MI
Re: Question about grounds for the digital dash (flyersfan1088)
Be sure to check that your bulbs are not burned out. The four "882" bulbs illuminate the gauges. These are halaogen bulbs, so do not touch them with bare hands as the oil from your hands will shorten the life of the bulbs.
After you pull that cluster once, it gets easier each time (unfortunately). In addition to the article by Gordon Killebrew, there was another (I think it was noted in an earlier post--if not, I'll find it). That one went into more detail, and walks you through the complete disassembly of the cluster. I thought I had mine fixed by just running that new ground wire and replacing the bulbs, but it would still go dim--with and without the turn signal/high beam lights coming on. I pulled everything apart and resoldered certain ground connections AND cleaned the connection between the top and bottom circuit boards. Thank god for those instructions, as I am NOT an electrical whiz. I felt very safe with thos instructions in hand!
Good luck...give the repair a try. It's not as tough as you might think.
Bill
After you pull that cluster once, it gets easier each time (unfortunately). In addition to the article by Gordon Killebrew, there was another (I think it was noted in an earlier post--if not, I'll find it). That one went into more detail, and walks you through the complete disassembly of the cluster. I thought I had mine fixed by just running that new ground wire and replacing the bulbs, but it would still go dim--with and without the turn signal/high beam lights coming on. I pulled everything apart and resoldered certain ground connections AND cleaned the connection between the top and bottom circuit boards. Thank god for those instructions, as I am NOT an electrical whiz. I felt very safe with thos instructions in hand!
Good luck...give the repair a try. It's not as tough as you might think.
Bill
Racer
Joined: Apr 2004
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From: Farmington Hills MI
Re: Question about grounds for the digital dash (TaylorMutts)
Here is a link to the other tech article I referenced. This is in very good detail, and was well worth following.
http://www.batee.com/corvette/index.shtml
http://www.batee.com/corvette/index.shtml
Thread Starter
Melting Slicks
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Re: Question about grounds for the digital dash (TaylorMutts)
This is what i've done so far: Taken the cluster apart, cleaned the connections inside, resoldered some points that looked bad, clenaed the connections at the side where the harness plugs in. Checked and cleaned the two grounds inside the cabin (one at the drivers side, one at the passenger side). Unless I'm missing something the ambient ground is the last thing i can do. I'm gonna do that this morning... I'll let you guys know how it turns out.