Dim Dash LCD Speed Display

[SteelBlueZR1]

Has anyone else had an issue with the LCD Speed/Gas gauge display being dim and gray vs. showing dark black digits? My car has very low mileage, and i wonder if there is corrosion on the pins on the back of instruments vs. grounds making bad contact. I notice that the LCD backlight dims when I press on the brake pedal at idle.

Where are the grounds for the instruments located and how do you access them to clean them? I read about someone who just cleaned the pins on the back of the instrument pane with alcohol and the connector and the display is now dark uniform black. Any sage input or solutions before I proceed to remove the instruments is appreciated?

[Kb7tif]

The lcd portion wears out. I have 3 exact same replacements and All have a different brightness.

[SteelBlueZR1]

Thanks for the feedback on this issue. In case I clean the contacts and grounds (does anyone know where the instrument grounds are exactly located?) and I still have very light LCD speedo numbers, are any of your LCD panels available for sale?

[ZR1@gmx.com]

My display has started dimming as I drive it... It slowly flashes from bright to dim, I hope to learn how to fix this too!

[RICHARD TILL]

Me 2.

[captcorvette]

Add me to the list. This same issue happens on my '90 ZR1 and my '90 & '91 roadsters.

[SteelBlueZR1]

So, I finally cleaned any corrosion on the pins on the back of the instrument panel and the connector with alcohol and steel wool, but the digital speedometer display is still dim. Has anyone else come up with a solution for the dim speedometer LCD display? I still plan to clean the ground at the driver's side foot well/speaker cover.

[Kb7tif]

The display gets weak, I have 3 over here and have 3 different brightness's
from almost unreadable to normal. All from the same car.


See if you can swap out a known good unit.
Ive been thru all of this- its rarely grounds
or this kind of thing.
All of the functions ( digital segments ) are controlled by the CCM and Pcm together. As far as anything but the backlighting .That rarely goes out.
Try a known good unit.

[mike100]

Is it the backlight? try turning on your headlamps and adjusting the dimmer lever to maximum brightness.

seems like my 95 LT1 car dimmer function used to work all the time regardless of headlamp function, but the early ones need the lamps on for the dimmer to adjust. they even made the gauge ink white instead of dark yellow on the 94-up cars...obviously these were a little challenging to see even new.

[Paul Workman]

If stepping on the brake causes change in the luminance, "grounding" is the first thing that comes to mind. The FSM should help. But, in the mean time, the two circuit ground reference points are on the back of the block at the edge of the bell housing, each right/left bolt is about 6 inches either side of top-center of the periphery. There are 4 lugs on one bolt, and 5 lugs on the other.

As for the connectors on the instrument cluster, there are two; the main one at the corner of the board, and the other is at the top, which serves the LCD pannel. Both connectors can be and should be replaced, if there is any sign of "frosting" (whiteish oxidation) on the pins. (I ran across those connectors a few times when I was searching for parts for the board. I'll see if I can dig them up again.)

P.

[rhipsher]

Mine did the same thing also. It would get bright then dim and it would be bright in one area and dim in another. But I found that every time I'd turn the dimmer switch all the way down then turn it up again everything was back to normal for a few seconds at least. That told me that the switch was the problem so I replaced it and have had no more issues. That's the best outcome. I sure would hate to have to tear into that dash.

[SteelBlueZR1]

Thanks to everyone for all the great feedback. All the LCD display is equally dim/gray vs. black digits. The backlighting does adjust with the dimmer switch when lights are on, but the digits remain poorly defined. I will check the other grounds you suggest when i change the oil at our next maintenance day. The car has just 6k miles, but maybe I do just need a new LCD crystal.