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Discussion Starter #1
Ever since purchasing my wagon the display has been intermittently blanking out.
Nothing would trigger it, sometimes short duration, sometimes not.
It was never 100% blackout, something was still always displayed.
Like just trip meter, just mileage, but always the speedo would blank out.

I did the pull & clean deal, no change. Saw thread on bad daughter board pin solder that wasn’t it either.

Yesterday I pulled it again because it was acting up worse.
On careful inspection believe I finally located the issue?
The lower display panel connector solder joints on backside of circuit board.
With magnification there were several joints that looked suspect.
There were what appeared to be circular cracks very hard to see, and impossible spot without magnifying.
So I removed old solder & resoldered all of them.
On reassembly the display seems brighter so I am hopeful this is finally the “fix”.

I’ll post an update after car gets enough road time to verify.
None of the other solder joints appeared to be in need of rework that I saw.

If you have a similar issue an inspection w/ a magnifying glass may be way to go.
 

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Discussion Starter #2
So far so good!

Did a 40 minute drive, and couple short errands the display worked 100% whole time Yay!
Looks like finally found/fixed the issue, hopefully for good.
 

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Discussion Starter #4
So problem came back with a vengeance!
Way worse than ever. Virtually useless blinking on/off non stop odometer constantly scrambling etc.

Started digging into wiring suspecting that since cluster itself seemed to be fine when it was working properly.

Nothing found until today. I noticed the odometer occasionally diplaying"km" while scrambling around.
On a hunch dug into wires going to the E/M & trip switches and BINGO!!
Source finally found...only took couple years.
 

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Good info. My cluster never was exactly right, but it got better with re-soldering the contact points on the small Speedo board. Ensuring that all grounds were clean and wiring in good shape. As well as a good strong battery and a set of high quality aftermarket heavy gauge battery cables.

In the process of doing all this I discovered this (disregard my poor speling)

https://www.impalassforum.com/vBulletin/26-electrical/256571-bad-ground-wire-i-p-harness.html
 

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Discussion Starter #6
Well today more of same but odometer scramble is gone.
Must be yet another wiring issue in harness somewhere...
I dug in and added jumper grounds on wires that should be grounded.
We'll see if that does it? If not have to dig deeper.

Annoying as hell every time I think it's "fixed" it starts flaking out again.
3 months it was rock solid...sigh
 

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Well today more of same but odometer scramble is gone.
Must be yet another wiring issue in harness somewhere...
I dug in and added jumper grounds on wires that should be grounded.
We'll see if that does it? If not have to dig deeper.

Annoying as hell every time I think it's "fixed" it starts flaking out again.
3 months it was rock solid...sigh

on 3rd gen camaro this is a common problem. circuit board soldering cracks at the pins on cir board. ..what they did to fix it was, just add more solder.. clean up the solder spot and give it a hit with a low watt soldering iron use flux solder small gauge stuff .. use denatured alcohol to clean it up.
 

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Discussion Starter #8
on 3rd gen camaro this is a common problem. circuit board soldering cracks at the pins on cir board. ..what they did to fix it was, just add more solder.. clean up the solder spot and give it a hit with a low watt soldering iron use flux solder small gauge stuff .. use denatured alcohol to clean it up.
If you read 1st post that was already done.
Since I added addition ground wires it hasn't done it again...
Time will tell if it's actually "fixed".
 

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If you read 1st post that was already done.
Since I added addition ground wires it hasn't done it again...
Time will tell if it's actually "fixed".

time will tell.. if it does it again resolder as I stated .. I have a 3rd gen camaro...
 

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Discussion Starter #10
For others who search & find this thread in future.

I bench tested it after initial solder work and again other day.
Pretty sure problem is/was with harness @ this point.
Should have done wiring 101 on the thing to begin with and verified continuity to grounds @ harness connectors.
C1 left connector B3
C2 right connector A6 & B4
Also E/M & Trip switches are momentary ground.
black & black w/ white wires.

Likely would have saved me time & frustration. While I did find/repair some solder connections I think it was a ground issue the whole time.
 

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For others who search & find this thread in future.

I bench tested it after initial solder work and again other day.
Pretty sure problem is/was with harness @ this point.
Should have done wiring 101 on the thing to begin with and verified continuity to grounds @ harness connectors.
C1 left connector B3
C2 right connector A6 & B4
Also E/M & Trip switches are momentary ground.
black & black w/ white wires.

Likely would have saved me time & frustration. While I did find/repair some solder connections I think it was a ground issue the whole time.
Babywag, did you remove the daughter board and redo all the solder points,including the 7 pins?
 

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Discussion Starter #12
I have not and since I could duplicate the issue by wiggling wiring going to the E/M & Trip switches 99.9% it would not have resolved.
From everything I've read the display goes totally dark when it's a ps issue.
When it occurred on mine something would always still be lit up.

Since I could also see the "km" sometimes pretty sure the issue is with the E/M switch and/or wiring on mine.

So far adding "jumper" grounds to wiring has resolved it, I can no longer wiggle the wires going to the switch and duplicate issue.
It also hasn't flaked out since adding them.

Gut tells me issue was created by aftermarket alarm install. Have already found/fixed issues with wiring due to it.
 

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Discussion Starter #13 (Edited)
Ugh beating the dead horse!

So once again issue came back waaay worse than ever.
Disassembled and redid power supply, no change.
Redid entire curcuit board, no change.

Found used/untested cluster @ local yard.
No display, swapped power supply, still no worky.
Swapped display & power supplies, total crap still.

Dug into dash harness checked all wiring, found nothing.
Took cluster back to yard for replacement, they located one after ~week.

This one lit up, however mileage ~32k off.
Called several places and prices to change ridiculous.

So as of right now have working cluster again but undecided on next step.
I was able to locate chip on display for odometer/mileage but in a VERY difficult spot to remove and swap w/ my old correct chip.

So after hours and hours of frustration all the "fixes" were not "fixes".
The problem with mine was the display unit itself.
@ this point just fed up w/ all wasted time.
Probably roll my own custom setup or try and locate a '96 Impala cluster?
Don't like z28 option and zero desire for screwing around with any other 94/95 clusters.
Not much faith in current one as it is a reman unit and the solder work quality was pretty poor.
To add to frustration there are differences in 94 & 95 units. Specifically the display units and the circuit board display connectors.
So individual parts won't just swap unless same year/style.
 

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Discussion Starter #14 (Edited)
Crossing fingers might work this time?

Once again bugging me about fixing this stupid thing.

Did another different repair we'll see if it holds up this round?
It's currently mounted in my Jeep so it'll get plenty of heat & vibrations.

 

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the 1995 4 post digi clusters are the best of the 3 years.Try to find a civi '95 4 post unit,usually in better shape.
 

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Discussion Starter #16
the 1995 4 post digi clusters are the best of the 3 years.Try to find a civi '95 4 post unit,usually in better shape.
funny you mention that...have a '95 cluster installed and gauges are way less accurate than the original '94 gauges.
 

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funny you mention that...have a '95 cluster installed and gauges are way less accurate than the original '94 gauges.
With the age and varying mileage of these 25 year old clusters,gauge accuracy from cluster to cluster can be different.Simply throw your 94 gauges into the 95 unit if you like them better.The 94-96 digi cluster gauges interchange.
 

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Discussion Starter #18 (Edited)
Already tried that, no change...probably different resistance values in circuit board?



It(95) had a reman sticker on back and some shotty solder work.
But it worked so it's being used...

So far the 94 cluster hasn't skipped a beat.
Probably going swap it back in once I correct the odometer.
Need to add ~900+ miles to it.

99% sure mileage is stored on chip on right.

 

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Yes I agree it's stored on chip on right in your pic.I've had luck rolling the numbers but not getting them to stay once changed.
 

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Discussion Starter #20 (Edited)
Sadly chip appears to be proprietary delco?
Have not been able to locate datasheet.
Tried several different methods/attempts @ reading it but no luck...

Just have to feed cluster vss signal for a while to bump mileage up.
An 8k signal makes it go 2x faster, but still will take a bit.
 
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