C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

LDC problems

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Old 01-01-2018, 01:09 PM
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preacher putz
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Default LDC problems

Have a 96 coupe, Lt1/auto. The display is barely readable, but all the
information is there. Any ideas of how to enhance this information???

tks Preacher Putz
Old 01-01-2018, 01:16 PM
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billschroeder5842
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Your display is beginning (or has) to give out.

Get in touch with Brian at batee.com. He has done work for lots of us (he did my climate control on my 89) and he is fair.
Old 01-01-2018, 04:02 PM
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pcolt94
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Originally Posted by billschroeder5842
Your display is beginning (or has) to give out.

Get in touch with Brian at batee.com. He has done work for lots of us (he did my climate control on my 89) and he is fair.
I believe the 80s cars use the polarized film that goes bad. The 96 (and 90s) care are not like that, they use LED displays.


Originally Posted by preacher putz
Have a 96 coupe, Lt1/auto. The display is barely readable, but all the
information is there. Any ideas of how to enhance this information???
There are many items that can be the problem. The photo cell sensor, transistor driver, and CCM.

Does the displays light up with the key or light up turning on the parking lights?

Take a flashlight and shine it at the photo cell (it's above the fuel info button on the dash with all the other buttons). Then put your finger over it. Is there a change in brightness of the dash display from bright to dark.

Need to do some research to get additional information and a direction.
Old 01-01-2018, 04:35 PM
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preacher putz
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Default Lcd

Originally Posted by pcolt94
I believe the 80s cars use the polarized film that goes bad. The 96 (and 90s) care are not like that, they use LED displays.



There are many items that can be the problem. The photo cell sensor, transistor driver, and CCM.

Does the displays light up with the key or light up turning on the parking lights?

Take a flashlight and shine it at the photo cell (it's above the fuel info button on the dash with all the other buttons). Then put your finger over it. Is there a change in brightness of the dash display from bright to dark.

Need to do some research to get additional information and a direction.
Lights up with either the key or turning on the parking lights.
The photo sensor seems to work. Bright with flash light, dark
when covering the photo sensor.

Problem is the bars or numbers are very weak???????

tks Putz
Old 01-01-2018, 05:02 PM
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pcolt94
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So we are talking about the rectangular speedometer display only ?

Is the tach, lights for the 4 gauges and red indicator lights OK ?

Double check fuses # 27 & # 38.
Old 01-01-2018, 06:09 PM
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preacher putz
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Default Lcd

Originally Posted by pcolt94
So we are talking about the rectangular speedometer display only ?

Is the tach, lights for the 4 gauges and red indicator lights OK ?

Double check fuses # 27 & # 38.
Yes the rectangular speedometer only... tach and lights for guages and the red lights are good. fuses 27 and 38 test ok.
Old 01-01-2018, 07:07 PM
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PaZaicC4
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Look at it thru a pair of polarized sunglasses and see if it is readable. If so, Your polarizing film is bad. Batee sells the replacement film.
Old 01-01-2018, 09:10 PM
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pcolt94
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Originally Posted by PaZaicC4
Look at it thru a pair of polarized sunglasses and see if it is readable. If so, Your polarizing film is bad. Batee sells the replacement film.
This is a 96 car and does not use the film as stated above. It uses a LCD display.

Originally Posted by preacher putz
Yes the rectangular speedometer only... tach and lights for guages and the red lights are good. fuses 27 and 38 test ok.
Do you know how to get the codes using the ALDL (DLC) connector by shorting pins 4 & 12. I'm not sure how this works out for an 96 since it's OBD2 codes for powertrain. A consumer scanner will not do this as it will only do engine codes in module 4. But what I am looking for are codes for module 1 which is the CCM. The CCM drives the LCD speedometer display. The LCD display uses digital data and performs self tests when key is first turned on. So if there is a code set for module 1 it might be a clue as to what is going on and just a good piece of information to know.

When the light sensor in the dash is at its lowest resistance it drives the display to full bright. Not easy to get to the light sensor does go bad and I don’t have much info about it. I assume the dimmer control on the headlight switch works OK (?).

Depending on where you end up and running out of ideas, possible the instrument cluster could be re-seated and give it a visual look.

Last edited by pcolt94; 01-02-2018 at 09:47 AM.
Old 01-02-2018, 07:25 PM
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Default Lcd

Originally Posted by PaZaicC4
Look at it thru a pair of polarized sunglasses and see if it is readable. If so, Your polarizing film is bad. Batee sells the replacement film.
We got a pair of polarized sunglasses, that did the trick. Thanks ever so much

Pr. Putz
Old 01-02-2018, 09:23 PM
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Originally Posted by PaZaicC4
Look at it thru a pair of polarized sunglasses and see if it is readable. If so, Your polarizing film is bad. Batee sells the replacement film.
Originally Posted by preacher putz
We got a pair of polarized sunglasses, that did the trick. Thanks ever so much

Pr. Putz
I knew for years the earlier cars of the 80s used film. But never heard of and always thought the 90 cars got away from the film and was just electronic all the way with the LCD display. I was puzzled and did some research and found this to be true. All I can say is good call and good information.

http://batee.com/corvette/dcrg/servi...96_repair.html

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