Recently I have developed a problem with my dash cluster in my 87 and that has to do with the brightness of the entire display.
Initially when I insert the key in and start it up, it is nice and bright but within seconds the brightness is reduced to about 50 % and very difficult to read during day light hours.
Also the collant temp/Volt reading display is now very weak as is the fuel economy/avg readout and just barely visible but only at night.
I have checked the headlight switch to see if I had turned down the cluster brightness but that is not the problem.
What are the fixes and any suggested sources to do the repairs on such problems?
Any help would be appreciated.

 

if you place your finger over the Photo cell, does it make a difference?

Are the Turn signals and Blue bright light indicator shining??

 

Try this.


http://www.batee.com/corvette/index.shtml

 

With the photocell check. There are also 4 backlighting bulbs for the LCD panels you may have some of them burnt out or making bad connections unless higher voltage is supplied during the clusters self test when the unit is first powered up.

 

I rebuilt mine with that Battee.com site...it was really quite easy. Taking the cluster out and finding the exact size NUT DRIVER proved to be the most difficult part of the entire task.

That was 2 trouble free years ago. and since I put the (wrong) replacement bulbs back in, it is too bright and I have to place a spit wad in front of the Photocell to dim it down a bit.

Sadly, the wrong bulbs are about $7 each and the right bulbs are ~$2 each but have to be ordered. Someone will have to chime in with the exact part number for the correct bulb and the place to order them.....

I know the OP hasn't replied with his exact issues...I'd just rather throw out what I know right away........it may jar some info loose from the OP.....

 

Please excuse my ignorance but where would be the photo cell located as I see nothing in the owners manual that pertains to it?
I have gently pushed on to the 2 areas where the light displays are very weak and no changes.
The turn indicators and the blue bright light which I assume is the high beam indicator are not displayed but however function in a normal manner when engaged as they were intended to do.
I appreciate the input from all of you.
One other question so please bear with me. Should the cluster have to be removed and possibly sent out, will this disable the vehicle in any way? I am not planning on driving it but may need to move it from time to time in and out of the garage.

 

Look at the left top of the cluster, you will see a round hole about 3/16 inch in diameter, this is the photocell and is where you put your finger over to block the light causing your cluster lamps to brighten. There are 4 incandescent lamps that illuminate the cluster, you should easily be able to see their location and/or lack of one or more being lit.
The lamps are number 882 and they are NOT $2 each, I wish they were. If you remove the dash cover over your cluster you will see 4 silver reflectors over these lamps and if you remove them you will be able to see which lamp/s are burned out. Wrap some masking tape around the lamp and pull on the overlap with pliers STRAIGHT out. If you turn the lamp, you will have to take the cluster out (a lot of work) because the parallel 2 pin lamps plug straight into a socket that rotates and is inserted behind the rear circuit board and if rotated, fall down inside the cluster. Replacement is with a piece of tubing over the lamp and still, push straight in, replace the reflectors and the dash cover.

 

^^One guy posted the actual catalog jpg...and yes they were $2 bux. Of course unless I can produce that info....I'm just spewing BS.

Jim, if your turn indicators and high beam indicator are not illuminated, that is a good thing.

As JFB said the Photodiode is on the upper left corner about 1/2 an inch away from your speedo....Mine is a square hole however.

The Light bulbs could be burned out or the Photo Diode could have gone bad and then I've read where this was caused by the actual Potentiometer on the headlight switch....

If you are capable of pulling the cluster to "send it out" then you can fix it on your own.


Please please please look at the Batee.com site, read that article he has on repairing the cluster.

 

When you find the photocell, the best way to check it is to shine a flashlight at it and see if the lights get brighter. You can get the bulbs on Ebay for about 25 bucks for all of them, they are Xenon and don't burn nearly as hot as the stock 882's which are halogen. I rebuilt mine using the info on the Batee site, I had cracked my center cluster by not resetting the small spring that holds it in place.

 

I did as you suggested, held the flash light up to the photocell and they did get much brighter. After turning off the Flashlight, within about 15 seconds or so, they went back into the dim mode.
I appreciate all the info you guys are sending.

 

When the cockpit is dark, the photocell dims the cluster lamps, that is what it is supposed to do.

 

Good, that means things are working. You may just have to clean the photocell up to make it work properly. Something may be blocking the light to it. Have you checked the bulbs yet?

 

Thanks Rich and will do a little clean up on the photocell as you have suggested.
Have not checked the bulbs yet but I suspect they may need replacing.
If so, will go with the Xenon type for all of the obvious reasons.
You guys have been a great help

 

I ordered 4 new Xenon replacement bulbs this morning on E Bay and hopefully will have them here before the end of the week.
Thanks to all of you who took the time to reply to my problem as it helped more than you know. I learned something from all of you and I am grateful.

Also JFB, your advice on the removal and replacement method will certainly come in handy when it comes time to do this.
Will let everyone know of the final results once this thing is completed.
Thanks again,
Jim

 

Sorry it took so long to get back to you but here is the update and the results of the repair.
A friend was kind enough to remove the dash cluster from the car and as mentioned earlier within this thread was a very easy procedure.
Once the cluster was removed, we discovered burnt out bulbs and it was evident that they were of the wrong value because of the burnt marks left on the circuit board from over heating.
I had ordered some new Xenon replacement bulbs (less heat and burn much cooler) and replaced all 4 of the old ones and reassembled everything.
What a difference! Can actually see everything again even in the brightest light and at night by using the headlight control can adjust the intensity to suit my needs.
One thing that I did discover, the brightness can't be turned up or down without the ignition key in the ON position.
Thanks again to all of you who contributed and the links that you supplied that made this job that much easier.
The entire thing took less than an hour to complete and would have taken less but we took the slow and easy method just to be on the safe side.
Hope this helps to anyone with a similiar problem.
Thanks again everyone.
Jim

 

^^Good Jim.....and I am glad you stated what you did about it being easier than you first estimated.

This is one of those intimidating jobs that many are apprehensive about taking on. However, once you are on the other side, you see that waiting is the wrong thing to do.....To anyone else thinking about this one........dig into this one quickly and you'll be pleased with how simple the job is and the results you get from it.

Jim, lemme ask, being honest and now that you are empowered with the knowledge that you now possess, if you had to do it over again, would you employ your friend again or would you be comfortable tackling this one on your own??

Spoiler answer I'm sure Jim would do it on his own

 

John,
Good question and frankly I would not be afraid to to it again on my own now that I have seen how easy it was.
Like many, I am easily intimidated when it comes to electronics especially in the modern era of high tech and circuit boards etal.
I came out of an era where a tune up on a car consisted of new spark plugs, wires, cap and rotor and a set of points just to give you an idea of where my mentality comes from.
It is people like yourself that makes being part of this forum all the worth while and your willingness to share your knowledge with other uninformed's such as myself.
Thanks again for your help, you were one of the reasons why I was able to get this thing done.

 

Really?? *wipes tear* Get out of town would ya??

OK, I'm going home now before the day takes a downward turn....

See you guys in a few days...I'll be relishing in the meantime

 

OK, Ok , Just don't let your head get to BIG......WW

 

LOL....too late.......

j/k