I am looking any place i can for people who are creative enough and electronicly minded enough to try to modify my 84 and 87 clusters to use LEDs for the the back-lights instead of the high heat vapor bulbs. Any ideas or suggestions? I am willing to for-go intensity changes to get this to work if it can be done??? I have spent years thinking that there has to be a better way.

If it is just a matter of changing bulbs to LEDS, that would be easy. They sell LEDS that run on 12 volts. They will have two leads attached to them. I can't remember how the bulbs attach in the housing, but it is probably a soft printed circuit. If it is, it still has copper for the connection points, and if you are real careful, and use thin silver solder and low heat, you can solder the leads from the LEDS to the copper pads the old bulbs connected to on the printed circuit. I do alot of electrical and electronic work, so if you get it apart, and need some help, let me know.

The test on the lighting conection at the cluster shows variable voltage coming in from the head-light switch. I think it is 1-8.? volts and there is a secondary voltage variation from the light sensor and i have no clue what the varition is or where it enters the circuit.
As far as the lights them-selves there are four that have their own removable (twist and pull) socket which i also think should be easy enough to solder LEDs to. I just don't have a clue what else in the cluster would need changed to let them work??? This why i need some-one who knows those clusters very intimately to help me pull this off. The one on my 84 is already not working through the light circuit...It shows serious discoloration in places because of the high load and the generated heat from the bulbs... I want to find a way to stop that.

The test on the lighting conection at the cluster shows variable voltage coming in from the head-light switch. I think it is 1-8.? volts and there is a secondary voltage variation from the light sensor and i have no clue what the varition is or where it enters the circuit.
As far as the lights them-selves there are four that have their own removable (twist and pull) socket which i also think should be easy enough to solder LEDs to. I just don't have a clue what else in the cluster would need changed to let them work??? This why i need some-one who knows those clusters very intimately to help me pull this off. The one on my 84 is already not working through the light circuit...It shows serious discoloration in places because of the high load and the generated heat from the bulbs... I want to find a way to stop that.

The voltage coming from the headlight switch is used just to dim the guages a little when you turn your headlights on. Which is achieved by adding a resistance in the line which will drop the voltage coming across the bulbs from the headlight switch. It also has a variable resistor called a reostat that dims the or brightens the back lighting when you turn the knob. But all this is done with a voltage drop at the headlight switch. With the headlight switch off, there should be 12 volts going to the back-lighting sockets.The lens them selves are LCDs and are just backlit liquid crystals. The back-lighting stays on constantly. Depending on how bright the backlighting is, is the only thing that will determine how bright your guages are. The liquid crystals are inpregnated into the glass lens. There is an electrical connection that is made to the lens through the little rubber feeling rectangular pieces that the lens rest on. Those rubber-like blocks are divided into sections to deliver electricity to different parts of the lens. When electricity is applied to a part of the lens, the liquid forms to a solid, and turns that section black. Most people think that it is lighting the sections up, but it is really blacking sections out. Ever notice that when you turn the ignition on, that all the lights are lit for a second. That is actually just the backlighting on with no electricity applied to the liquid crystals in the lens. That is also why you see the color in the lens even when they are off. So what I'm getting at, is that it still should be a matter of just changing bulbs to LEDs because the back-lightings intensity only determines the brightness of the guages. The only problem I see, is I don't know the working voltage range of the LEDS. I mean, I'm not sure if they can be dimmed by a voltage drop. They may be only on or off. If the voltage drops, they may just turn off instead of dim. That is something I'll have to research. Corvette Central sells a fix it yourself gauge cluster book for $30.00. If you are really serious about this, it might be a good investment. Hell, it has been at least two years since I replaced one of my lens, so I can't remember what the bulb orientation looks like, but I'm sure you could find some way to connect the LEDs.

I know that this is an old post,

Just placing a link for any one to replace there bulbs in there cluster for LEDs ones. They work great and cost 50 + shipping.

Main link
http://www.usmracer.com/

LEDs link
http://www.usmracer.com/USM-TrueColor-LED-Bulb-Upgrade-for-Corvette-1984-89_p_5557.html

Xero420,

THANK-YOU for posting this. :thumbsup3:
I haven't been able to keep up on alot of the suppliers i used to watch and/or work with since i got sick in December. Finding out i have/had cancer in Feb. has taken a toll on my contacts every-where since i have dropped off the radar between major chest sugery in May and the chemo starting this month. It is just impossible to find energy to do much.

I knew after talking with 2 of the developers at USMRacer.com that they WOULD eventually find an answer to the problem i had finding LED replacements for these. They did a great job getting the color shades of blue i wanted to make me a custom insert as well. These guys are top notch to work with and i believed them 100% when they promised to keep looking into an LED mod...They did say it might take a while but they DID come through.:eek2::woowoo::drool5:
I would suggest this to any-one who has a digital cluster. If you have had problems with back light issues this might be the perfect cure. I KNOW the circuit boards will love this mod.:patriot:
As soon as i can see some kind of an income again i will be getting this kit for my 87...if i don't have to sell it. I had to sell the 84 to stay up with bills even before the cancer.