1990 dash gauge cluster problem. HELP!
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,011
Likes: 1
From: Marietta Pa
St. Jude Donor '10-'11-'12-'13-'14
1990 dash gauge cluster problem. HELP!
So here's the deal:
I recently got my 1990 out of storage, and noticed an issue (had been doing it before I put it in storage last year).
The center digital display works intermittently at best. It seems like when I plug the trickle charger in during storage, then drive it, the screen won't light up at all (no mumbers or anything). If I drive it for a few days without charging, some numbers will come back, it will sporadically work here and there, or it will work then freeze in almost a cycle.
It basically cycles between not working at all, to numbers coming on the screen without doing anything, to displaying the speed/gas/mileage/etc for a few seconds before freezing, to completely bugging out and giving me random speeds/gas gauge cycling between full and empty, etc.
What could be causing this? The other gauges work fine, it's just annoying trying to guess my speed based on RPMS cause my digital display won't work.
Thanks for the huge help in advance guys, this is really frustrating me!
I recently got my 1990 out of storage, and noticed an issue (had been doing it before I put it in storage last year).
The center digital display works intermittently at best. It seems like when I plug the trickle charger in during storage, then drive it, the screen won't light up at all (no mumbers or anything). If I drive it for a few days without charging, some numbers will come back, it will sporadically work here and there, or it will work then freeze in almost a cycle.
It basically cycles between not working at all, to numbers coming on the screen without doing anything, to displaying the speed/gas/mileage/etc for a few seconds before freezing, to completely bugging out and giving me random speeds/gas gauge cycling between full and empty, etc.
What could be causing this? The other gauges work fine, it's just annoying trying to guess my speed based on RPMS cause my digital display won't work.
Thanks for the huge help in advance guys, this is really frustrating me!
Instructor
Joined: Jun 2008
Posts: 173
Likes: 0
From: Norman OK
It basically cycles between not working at all, to numbers coming on the screen without doing anything, to displaying the speed/gas/mileage/etc for a few seconds before freezing, to completely bugging out and giving me random speeds/gas gauge cycling between full and empty, etc.
Also, you may need to clean the connectors to the CCM or the pins on the LCD itself. The LCD pins and socket in the cluster can wear over time. Checking that will require cluster removal and partial disassembly. While the LCD is bugging out, if you give the top of the dash a hard smack with your hand right above the cluster, does it change the LCD readout?
Check for codes, give it a whack and report back....
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,011
Likes: 1
From: Marietta Pa
St. Jude Donor '10-'11-'12-'13-'14
The LCD receives it's data signals from the CCM. To check for CCM faults, Jumper Pin G of the ALDL to ground Pin A. Stored fault codes will be displayed in the LCD in place of the speed numbers.
Also, you may need to clean the connectors to the CCM or the pins on the LCD itself. The LCD pins and socket in the cluster can wear over time. Checking that will require cluster removal and partial disassembly. While the LCD is bugging out, if you give the top of the dash a hard smack with your hand right above the cluster, does it change the LCD readout?
Check for codes, give it a whack and report back....
Also, you may need to clean the connectors to the CCM or the pins on the LCD itself. The LCD pins and socket in the cluster can wear over time. Checking that will require cluster removal and partial disassembly. While the LCD is bugging out, if you give the top of the dash a hard smack with your hand right above the cluster, does it change the LCD readout?
Check for codes, give it a whack and report back....
Tried that, doesn't work.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
Use the FSM to locate the various and many grounds and clean, tighten and inspect.
The most important group of 4 or 5 is above the oil filter either on the block or the trans bellhousing. Might also look at the jumper post and check all the power leads there. thats where your ecm and dash get power.
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,011
Likes: 1
From: Marietta Pa
St. Jude Donor '10-'11-'12-'13-'14
Any other ideas/suggestions?
Going to check the grounds this weekend, as well as possibly pull the dash out and check the connections behind it.
Which ground should I be looking at? The cluster on the bellhousing at the 11 o'clock position (if I remember that right?).
Anything else while I'm up there in case those two things don't fix the issue, or is it a rebuild/replace by that point?
Going to check the grounds this weekend, as well as possibly pull the dash out and check the connections behind it.
Which ground should I be looking at? The cluster on the bellhousing at the 11 o'clock position (if I remember that right?).
Anything else while I'm up there in case those two things don't fix the issue, or is it a rebuild/replace by that point?
Melting Slicks
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
There are ground wires attached to the frame @ the front of the battery tray. Found them when cleaning the air bag sensor on the '90. They may not fix your issue but it seems that clean grounds are important on Vettes.
