91 Dash LCD question/problem>>
Thread Starter
Race Director
Joined: Mar 1999
Posts: 12,597
Likes: 237
From: Bartlett Illinois
91 Dash LCD question/problem>>
I have 91 dash wiring and a 91 CCM but the Cluster is from a 94.
here is a picture of the key on power up/Self-test of the LCD.. the whole panel seems to work fine
But after the power up self test this is what I see
Any suggestions as to where to look for a problem? The CCM is BRAND New and has not had the TECH 1a connected to program it yet. When I bought the cluster I was told it worked but....
Thanks
here is a picture of the key on power up/Self-test of the LCD.. the whole panel seems to work fine
But after the power up self test this is what I see
Any suggestions as to where to look for a problem? The CCM is BRAND New and has not had the TECH 1a connected to program it yet. When I bought the cluster I was told it worked but....
Thanks
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Joined: Mar 2002
Posts: 65
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From: sharpsburg GA
Re: 91 Dash LCD question/problem>> (-=Jeff=-)
Hello,
I have a 90 and my cluster is doing some strange things also. In the morning when I start up I will only get half numbers and frozen mph readings, but as i drive along the screen will straighten it self out. Also my tach will peg out and slam back to zero when i start the car. It sure does act like a bad ground. When you put your cluster in was there a ground wire in the plug? Can you follow it? I have been trying to locate a wiring diagram for the cluster ground with no luck as of yet.
I have a 90 and my cluster is doing some strange things also. In the morning when I start up I will only get half numbers and frozen mph readings, but as i drive along the screen will straighten it self out. Also my tach will peg out and slam back to zero when i start the car. It sure does act like a bad ground. When you put your cluster in was there a ground wire in the plug? Can you follow it? I have been trying to locate a wiring diagram for the cluster ground with no luck as of yet.
Instructor
Joined: Mar 2002
Posts: 110
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From: youngstown Ohio
Re: 91 Dash LCD question/problem>> (-=Jeff=-)
I have a 90 and sometimes when I start it the dash will not light up at all. I have to put on my parking lights on to see the dash. However, If I just drive it for a while without turning on the lights, The dash will get brighter and eventually light up on its own. I am going to have a friend look at it in May (not a big enough problem to do it sooner) I will ask him about your problem and get back to you if you have not already found out the problem by that time.
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Re: 91 Dash LCD question/problem>> (-=Jeff=-)
I'm not so sure that a '92 and up cluster will work with a '90-'91 CCM/ECM. The cluster for newer vettes displays quite a bit more info than the '90-'91 does. For instance, in my '90, I can't display the digital temp for oil on the cluster, I only get the idiot guage. Later clusters like the one you have could display it. But since the '90-'91 CCM is not setup for that I wonder if there are wiring differences. Also, and this may not matter, the layout of the cluster numbers are different.
On mine, the layout looks like this:
Fuel on top, speed on bottom. Maybe there's differences there that are keeping the thing from working right?
On mine, the layout looks like this:
Fuel on top, speed on bottom. Maybe there's differences there that are keeping the thing from working right?
Thread Starter
Race Director
Joined: Mar 1999
Posts: 12,597
Likes: 237
From: Bartlett Illinois
Re: 91 Dash LCD question/problem>> (Marcho Polo)
Craig you know that is what I was thinking.. I may just try to get a 94 CCM and try that.. the wiring seems close.. OR I will get a 91 cluster and besure it works.. then swap the White Letter overlays from my 94 cluster.. But I bet you are right the data being sent is different.
Jeff
Jeff
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Joined: Mar 2000
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From: Woodstock GA
Re: 91 Dash LCD question/problem>> (-=Jeff=-)
Jeff;
Just get the correct LCD don't try to mix and match there are many small changes from year to year even in CCMs have small changes in them if they don't line up correctly they will not be able to communcate with the LCD and or PCM. Unless you know for sure because you know someone else has done it, keep the correct year PCMs, ECMs, CCMs, and LCD,s. I just don't think the 94 LCD will work with you car.
David Fulcher
Just get the correct LCD don't try to mix and match there are many small changes from year to year even in CCMs have small changes in them if they don't line up correctly they will not be able to communcate with the LCD and or PCM. Unless you know for sure because you know someone else has done it, keep the correct year PCMs, ECMs, CCMs, and LCD,s. I just don't think the 94 LCD will work with you car.
David Fulcher
