I’m hoping someone can help me with a problem I’m experiencing with my Digital dash.
I have searched the internet with no luck for days on end. My first problem is the digital readout works fine until I go over 35 mph, then it fluctuates all over the place, but if I keep the car under hard acceleration it reads correctly. I have changed the buffer with no difference, and the VSS module seems to be working correctly when hooked up to a drill. Any help with this would be greatly appreciated.
The second problem is with the digital odometer panel. It does not work at all in my car except for the back lighting, but when I put it into another 88 gta it works as it should, any suggestions on this issue.

 

I know for one I can't read that font... maybe that's why no one else responded.

 

Thanks, I will change the font.

 

I have the same problem with my odometer screen, but sometimes it randomly comes on, for example, if I fill the gas tank up, it stays on for a while, but eventually shuts off...

As for the speedometer, I have had a similar issue before, but after pushing up on the fuse block it seems to stop fluctuating. You should start by checking the courtesy fuse. If it is blown, it will read incorrectly and will fluctuate. (if the interior lights and radio don't work, then it indicates the fuse is blown). You should also check the wiring, make sure none of it is pinched, melted, etc.

 

All my fuse’s are good and everything else is working fine. Doesn’t matter if the feul tanks full or empty. I pulled the cluster out and replaced it with a spare one I had out of another 88 GTA. I thought I had my problem solved. The odometer panel and all the buttons where working until I started the car and tied to test it. I put it in gear and started to throttle up the car and the speed-o would only go to 23 mph before starting to fluctuate all over the place again. and now the odometer panel is dead again.

 

I'd check the speedo gears - on the VSS and on the tailshaft - to be sure they are not chewed up.

 

I have checked them and they look like new, also checked that the clip that holds the drive gear to the tail shaft was in place and holding correctly, everything checked out OK.

 

Worth checking those gears just too be sure all the teeth are still "meshing" properly.

If you've pulled your cluster and put it in another car - and it worked fine,... I've got to think the cluster is OK. If you put another KNOWN GOOD cluster in your car and it worked - then failed in a similar way as the original, then it seems obvious that your car/wiring is the problem.

If your sure the cluster is getting power the way it should thru all teh plugs,... (Fuses OK, Power wiring probed to verify voltage at the power inputs @ the cluster plugs ) I'd "jumper" a ground wire to every ground lead at each of the cluster plugs.

I do NOT know if this is related or not;

There is a support bracket the is located behind the dash housing that is placed at the center of the firewall. I'm pretty sure that the top of it can bee seen if the dash pad is removed. ( I think it's accessable from the bottom too - but only after several other parts are removed first. )

This bracket has a ground wire screwed to it. I *think* this wire is a ground for the cluster. It's a major PITA to gain access to this ground wire and that's why I recomend "jumping' each of the ground connections directly at the cluster plugs. ( hopefully you will not need to try to reach that bracket / ground wire ! )

 

Notes Car "1" is the one I'm trying to fix.
Car "2" refers to the parts car.


The digital speedometer in car "1" I'm trying to fix reads accurate to a speed of 35 MPH and then jumps all over the place. the odometer panel does not show anything. Believing that the odometer card was the problem I purchased a parts car with the same dash and tried putting the odometer card from car "2" into car "1". The card from car "2" would not work in car "1" I then took the card from car "1" and installed it into car "2" and it worked.
Now suspecting that the problem was in the speedometer cluster I took the dash cluster from car "2" and put it into car "1" this seamed at first to have fixed the problem as everything was lit up and working including the odometer panel and all the buttons to change the functions when the key was put in the run position.
I then started the car put it into drive and started to throttle up and this time the speedo read up to 23MPH and started to jump all over the place again, I looked over at the odometer panel and it was dead again.
After removing the speedo cluster I noticed the damage on the rear of the panels circuit ribbon and then looking over the back of the cluster from car "1" found it to have the exact same damage in the exact same spot.
I wish I would have looked over the cluster from car “1” before I installed the one from the parts car but I didn’t BAD ME !!!!
How I have 2 s****ed up clusters and still don’t know the cause of the problem. I’m now suspecting the problem may be in the odometer card. I traced the ribbon and it goes to the #16 pin on the panel which indicates that it is the ignition power from cluster fuse panel
I will try to up load a photo of the back of the panel.

 

I couldn't figare out how to up load a photo, any idea's

 

[quote=bad dash GTA;5807952]Notes Car "1" is the one I'm trying to fix.
Car "2" refers to the parts car.


The digital speedometer in car "1" I'm trying to fix reads accurate to a speed of 35 MPH and then jumps all over the place. the odometer panel does not show anything. Believing that the odometer card was the problem I purchased a parts car with the same dash and tried putting the odometer card from car "2" into car "1". The card from car "2" would not work in car "1" I then took the card from car "1" and installed it into car "2" and it worked.
Now suspecting that the problem was in the speedometer cluster I took the dash cluster from car "2" and put it into car "1" this seamed at first to have fixed the problem as everything was lit up and working including the odometer panel and all the buttons to change the functions when the key was put in the run position.
I then started the car put it into drive and started to throttle up and this time the speedo read up to 23MPH and started to jump all over the place again, I looked over at the odometer panel and it was dead again.
After removing the speedo cluster I noticed the damage on the rear of the panels circuit ribbon and then looking over the back of the cluster from car "1" found it to have the exact same damage in the exact same spot.
I wish I would have looked over the cluster from car “1” before I installed the one from the parts car but I didn’t BAD ME !!!!
How I have 2 s****ed up clusters and still don’t know the cause of the problem. I’m now suspecting the problem may be in the odometer card. I traced the ribbon and it goes to the #16 pin on the panel which indicates that it is the ignition power from cluster fuse panel
I will try to up load a photo of the back of the panel.

I hope this works

 

At that point the original cluster/printed circuit was already bad I assume.


Seems as if the card itself "could" have caused the burnt printed circuit to the original cluster,... then to the second cluster once the original card was placed into it.

I don't KNOW that, but it seems reasonable based on your description. I would NOT install the card from the original cluster into ANY other cluster going forward,....... at this point I simply couldn't trust it !

 

here are a few more pics. and yes your right, if I would have checked over the cluster from car "1" I might have fixed the problem and been a happy camper. Putting in the odometer card from car "1" was a big mistake. I do have a bit of good news, A friend has taken the cluster from car "1" to work where he has access to a insterment Teck who may be able to repair the ribin circuit and I found a company in Calgary AB. that was a repair shop for GM's digital panels. I sent them photo's of he dash and the suspect problems. i'm hoping they will help with this issue. I will keep you up dated.

 

I'm going to check the G118 ground wire as it seams to be common to both pin connectors in the dash, I looked for it yesterday but couldn't find it. I know it's located on the back of the passenger side head of the motor, but haven't figured how to get at it. I hope I don't have to take all of those pipes out to check it.

 

did you ever fix this? my odometer is also not working and i assume its the card. when car starts for few seconds it shows up and then fades. odometer is lit up but no digits on it. i changed dimmer already. also car does not record mileage when driven. makes me think odometer circuit board is bad. i started looking for a new dash to replace it. (noone sells the card). It would be great if someone figured out the fix for this. I read a ton of posts both here and on gta sourse with ppl having same issue. noone seems to have the answer.

 

I replaced the odometer circuit board. But I swapped the mileage chip with my original. If you want to keep your original mileage, you'll need to do this. I can take a pic of what I am talking about if you want.

 

i figured that out but thank you. now i just gotta find a digital dash with working odometer circuit board.