Hello, Joe M over at About.com (Car Repairs) suggested I post here and Joe mentioned that "Hammer time" may have some knowledge on my 2002 silverado (4.8L) instrument display problem. First I'll go thru the basic background. I noticed that I did not have the +12 volts on my OBD 2 connector and Joe M over at About.com (Car Repairs) sent me a number of schematics. I proceeded to troubleshoot the circuit accessing the under the hood fuse housing and noticed that I had +12 on one side of the cigar fuse (feeds OBD 2 connector ) but not the other, and since the fuse was good I decided I needed to get to the back of the block to see if it was supplying the +12. I pulled approx half of the fuses toward the cabinet fire wall (passenger compartment direction) prior to unscrewing the retainer bolt on the back of the connector assy underneath side, of the under the hood fuse housing. My logic was it would come off easier. The issue with the +12 volt turned out to be that the input side (+12) of the fuse receptable was a little enlarged and I have that resolved good enough to have +12 at the obd 2 conn. After assembling everything I noticed that my instrument display is irregular and yes at some point I took it apart again to check everything visually and everything appears to be OK. Display was normal just prior to my pulling of fuses and reassembly. I'll pasted in the irregularities of the display below:

Gas gauge on zero but near full tank, collant temp gauge not working, high beam indicator not lit but lights still work
> normal, cruise light does not light but works normal and gear selector
> area does not light up. I just drove it around a bit and I can drive
> it and every thing works yet the info area flashes between battery on discharge, low fuel, and security. My charging is 14.2 to 14.6 vdc, I have a full tank of gas. Now when I turn it off the Security light stays on continually. I do not believe the security light ever came on at all for I have never noticed it over the last year of daily use. When this initially happened a few weeks ago I googled the security light and found some interesting reset sequences and have tried all those plus pulling battery power for 30 minutes, and my own re-fusing (powering ) sequences and nothing has changed.

Lastly, if it's determine that it needs a display, does it require specialize programming which would reduce the advantage of using a salvaged display for the repair??

Thanks in advance.

I'm afraid you may have gotten a little over your head here. That dash cluster is basically a big computer that is integrated with the Body Control Module and other Modules and they all communicate with each other. It requires some real specialized equipment to diagnose anything here. At the very least you need a Tech2 with updated software. You can't just go to a junkyard because the VIN of the vehicle is programmed into the cluster and without that, it will not communicate with the other modules. Your going to need either the dealer or a very well equipped independent electrical specialty shop to get to the bottom of this one.




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