Bellrose

Hey all. I'm going to tear apart my dash to get at the digital cluster, but before I do, I was wondering if anyone knows where I can get some schematics or system overview drawings of the cluster unit. I'm an electrical engineer, so I can probably fix the dash myself, I just need a reference. If not, I'll be reverse engineering on the fly (not fun). I already have wiring diagrams for the dashboard, but I have nothing for the circuits within the cluster unit. If anyone could help me get these schematics, or possibly know who or where in Chevy I could contact that would be great.

Also, if anyone cares, the problem (which I've seen many others have had) is that my gauges are out of sorts and my digital display goes black when the headlights are turned on. Weird thing is, if I turn the dimmer all the way down the display comes on at it faintest setting. Any suggestions are always welcome!

Twin_Turbo

iTrader: (25)

sounds like you have a ground issue

Bellrose

I just posted this on another forum, but here it is again anyways:

After playing around last night I'm fairly certain that I've isolated the problem to the digital cluster unit. I see what you're saying about the dimmer switch in the left pod; however, all of the incandescent lights in the car which are dimable (the left and right pods, shifter and radio light) are all properly controlled by the dimmer. Because those lights are being properly controlled with the dimmer switch, the light module can be eliminated from the equation.

The only problem where dimming is occuring is in the cluster unit. This is what's going on. With the headlights off, the speedo, tach and all other lights function as expected. Another interesting twist is that my gauges (oil fuel temp and batt.) are all reading incorrectly. With the head lights on the speedo and tach go black and the gauges all peg. The oil, batt, and fuel all peg to the empty position and the temp pegs to the hottest position. If I turn my dimmer all the way down, I can see the speedo and tach in their faintest setting.

From the drawing I have, all of the gauges are tied into the solid state "computer" which also controls the digital display. So it makes sense that all of these problems are linked together. It is peculiar that the display works when the dimmer is at it's lowest setting but turns off when it is higher.

My guess is that the dim setting is the default for the computer chip and it has an external input to increase the the brightness of the display. Something to do with this external input is buggered and not giving the correct signal to the cpu when the dimmer switch is increased. This is causing the digital display to go black.

It would also be logical is it was a problem external to the computer chip as it appears to be affecting the performance of the gauges. My hope is that there is a blown resistor or capacitor which is controlling the power feed to the chip and the gauges. I hope this because it is easy to fix haha.

Then again I could be out to lunch on this one. Just my theory. I'll be looking into it more soon and I'll keep you posted. If anyone has their own theory, please let me know!

Bellrose

I regret to inform you all that I was rear ended two days ago and my car has been written off. I don't think they will let me buy it back, so it's going to the scrap yard. Looks like my digital cluster issues will remain a mystery. Truly a sad day for me